Using Text Anchor to add 3 signatures

I have a client who is using REST API to create package. They were able to create a package with one signature, but they got error 500 when adding 3 signatures. Payload: `{ "name":"TEST 32.pdf", "approvals":[ { "signed":null, "accepted":null, "data":null, "fields":[ { "type":"SIGNATURE", "width":200, "height":50, "page":0, "extract":false, "extractAnchor":{ "text":"Dealer Signature", "index":0, "width":150, "height":40, "anchorPoint":"TOPRIGHT", "characterIndex":17, "leftOffset":0, "topOffset":0 } }, { "type":"SIGNATURE", "width":200, "height":50, "page":0, "extract":false, "extractAnchor":{ "text":"Dealer Signature", "index":1, "width":150, "height":40, "anchorPoint":"TOPRIGHT", "characterIndex":17, "leftOffset":0, "topOffset":0 } }, { "type":"SIGNATURE", "width":200, "height":50, "page":0, "extract":false, "extractAnchor":{ "text":"Signed for and on behalf of Dealer\/Supplier", "index":0, "width":150, "height":40, "anchorPoint":"BOTTOMLEFT", "characterIndex":1, "leftOffset":0, "topOffset":10 } } ], "role":"Dealer" } ], "extract":true }` The response they got :

Cake\Network\Http\Response Object
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    [_body:protected] => {"status":"","id":"631a735b9dba34f3","approvals":[{"role":"Dealer","id":"uEh2GmWB890Z","signed":null,"accepted":null,"data":null,"fields":[{"validation":null,"page":6,"top":774.5703735351562,"id":"sXtQe37Gph45","subtype":"FULLNAME","height":40.29999923706055,"binding":null,"extractAnchor":null,"left":157.2237091064453,"width":149.5,"extract":false,"data":null,"type":"SIGNATURE","value":"","name":"sXtQe37Gph45"}],"name":""}],"pages":[{"top":0.0,"id":"ae7ae014bfb7e7f4_1.png","height":1095.0,"left":0.0,"width":774.0,"version":635205,"index":0},{"top":0.0,"id":"ae7ae014bfb7e7f4_2.png","height":1095.0,"left":0.0,"width":774.0,"version":635206,"index":1},{"top":0.0,"id":"ae7ae014bfb7e7f4_3.png","height":1095.0,"left":0.0,"width":774.0,"version":635207,"index":2},{"top":0.0,"id":"ae7ae014bfb7e7f4_4.png","height":1095.0,"left":0.0,"width":774.0,"version":635208,"index":3},{"top":0.0,"id":"ae7ae014bfb7e7f4_5.png","height":1095.0,"left":0.0,"width":774.0,"version":635209,"index":4},{"top":0.0,"id":"ae7ae014bfb7e7f4_6.png","height":1095.0,"left":0.0,"width":774.0,"version":635210,"index":5},{"top":0.0,"id":"ae7ae014bfb7e7f4_7.png","height":1095.0,"left":0.0,"width":774.0,"version":635211,"index":6},{"top":0.0,"id":"ae7ae014bfb7e7f4_8.png","height":1095.0,"left":0.0,"width":774.0,"version":635212,"index":7},{"top":0.0,"id":"ae7ae014bfb7e7f4_9.png","height":1095.0,"left":0.0,"width":774.0,"version":635213,"index":8},{"top":0.0,"id":"ae7ae014bfb7e7f4_10.png","height":1095.0,"left":0.0,"width":774.0,"version":635214,"index":9},{"top":0.0,"id":"ae7ae014bfb7e7f4_11.png","height":1095.0,"left":0.0,"width":774.0,"version":635215,"index":10},{"top":0.0,"id":"ae7ae014bfb7e7f4_12.png","height":1095.0,"left":0.0,"width":774.0,"version":635216,"index":11},{"top":0.0,"id":"ae7ae014bfb7e7f4_13.png","height":1095.0,"left":0.0,"width":774.0,"version":635217,"index":12},{"top":0.0,"id":"ae7ae014bfb7e7f4_14.png","height":1095.0,"left":0.0,"width":774.0,"version":635218,"index":13},{"top":0.0,"id":"ae7ae014bfb7e7f4_15.png","height":1095.0,"left":0.0,"width":774.0,"version":635219,"index":14},{"top":0.0,"id":"ae7ae014bfb7e7f4_16.png","height":1095.0,"left":0.0,"width":774.0,"version":635220,"index":15},{"top":0.0,"id":"ae7ae014bfb7e7f4_17.png","height":1095.0,"left":0.0,"width":774.0,"version":635221,"index":16},{"top":0.0,"id":"ae7ae014bfb7e7f4_18.png","height":1095.0,"left":0.0,"width":774.0,"version":635222,"index":17},{"top":0.0,"id":"ae7ae014bfb7e7f4_19.png","height":1095.0,"left":0.0,"width":774.0,"version":635223,"index":18},{"top":0.0,"id":"ae7ae014bfb7e7f4_20.png","height":1095.0,"left":0.0,"width":774.0,"version":635224,"index":19},{"top":0.0,"id":"ae7ae014bfb7e7f4_21.png","height":1095.0,"left":0.0,"width":774.0,"version":635225,"index":20},{"top":0.0,"id":"ae7ae014bfb7e7f4_22.png","height":1095.0,"left":0.0,"width":774.0,"version":635226,"index":21},{"top":0.0,"id":"ae7ae014bfb7e7f4_23.png","height":1095.0,"left":0.0,"width":774.0,"version":635227,"index":22},{"top":0.0,"id":"ae7ae014bfb7e7f4_24.png","height":1095.0,"left":0.0,"width":774.0,"version":635228,"index":23},{"top":0.0,"id":"ae7ae014bfb7e7f4_25.png","height":1095.0,"left":0.0,"width":774.0,"version":635229,"index":24},{"top":0.0,"id":"ae7ae014bfb7e7f4_26.png","height":1095.0,"left":0.0,"width":774.0,"version":635230,"index":25},{"top":0.0,"id":"ae7ae014bfb7e7f4_27.png","height":1095.0,"left":0.0,"width":774.0,"version":635231,"index":26},{"top":0.0,"id":"ae7ae014bfb7e7f4_28.png","height":1095.0,"left":0.0,"width":774.0,"version":635232,"index":27},{"top":0.0,"id":"ae7ae014bfb7e7f4_29.png","height":1095.0,"left":0.0,"width":774.0,"version":635233,"index":28}],"external":null,"extract":false,"index":4,"data":null,"description":"","fields":[],"name":"TEST2  32","size":200373}
    [_xml:protected] => 
    [_json:protected] => 
    [_exposedProperties:protected] => Array
        (
            [cookies] => _cookies
            [headers] => _headers
            [body] => _body
            [code] => _code
            [json] => _getJson
            [xml] => _getXml
        )

    [_headers:protected] => Array
        (
            [Server] => nginx
            [Date] => Fri, 29 Jan 2016 10:44:05 GMT
            [Content-Type] => text/html
            [Connection] => close
            [Expires] => Fri, 29 Jan 2016 10:44:05 GMT
            [Cache-Control] => no-cache, no-transform, max-age=0
            [X-Powered-By] => Undertow 1
        )

    [_cookies:protected] => Array
        (
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    [_version:protected] => 1.1