Please share minimal playground demo.
https://playground.jsreport.net/

Well if you send to col helper always constant 1, it will always end with constant 2. You will need probably need use 1

https://handlebarsjs.com/guide/builtin-helpers.html#each

The reports aren't running likely, just the profile information wasn't updated.
This can happen when the process is stopped forcibly and running reports don't get updated. We will add some logic to clean such profiles. https://github.com/jsreport/jsreport/issues/1006

Now you can just ignore such old profiles because they get rolled out anyway shortly. jsreport keeps just 1000 last profiles by default.

Please try to clean the _tempPath you use and restart the app.

The problem is described in this older but still valid post
https://jsreport.net/blog/using-input-data-in-html-page-inline-javascript

jsrender/handlebars isn't doing JSON serialization when you do this
data: [{{:Testdb5dcd55106b4e82b79932720bcea516}}]
but it's own "to text" serialization so you end with this
data: [43934,11744,52503

The solution mentioned in the post works well, but jsreport has since v3 already system helper for you.
https://jsreport.net/learn/templating-engines#tojs-data-

data: {{:~toJS(Testdb5dcd55106b4e82b79932720bcea516)}}

Hint: I like to use text recipe for troubleshooting to see whats exactly is printed by handlebars before being evaluated by chrome.

The helper's parameters can be calculated dynamically using handlebars subexpressions
https://handlebarsjs.com/guide/expressions.html#subexpressions

{{#xlsxAddImage "test" "sheet1.xml" (acalcColumnFromHelper x) 0 1 1}}
{{asset "myImage.png" "base64"}}
{{/xlsxAddImage}}

Hm, I can't find this in the actual pdf standard
https://opensource.adobe.com/dc-acrobat-sdk-docs/pdfstandards/pdfreference1.6.pdf

Its probably not supported in the current implementation, but will later check what that about.

I believe you use the xlsx recipe.
And the transformation approach with the xlsxAdd and other helpers used to update the xml source files. Right?
In this case, you should use documented xlsxAddImage helper and just place images to the right cells. Any problem with that?

What value are you trying to pass there?
Did you try to open the result in the desktop acrobat reader? The browser's native support for pdf forms is limited.

https://jsreport.net/learn/configuration#web-server

The default is now 50mb and can be increased using config extensions.express.inputRequestLimit.