InfoPath Dev

Hello! So i have this Infopath 2013 form that uses Web Service UpdateListItem with CAML query to update a list item. This works just fine in Preview mode, but as soon as i upload it as a Browser Form it crashes with an Log-ID of 5567. I am trying to upload it to SharePoint 2019 On Premise server. I have read here on the forum that it isnt possible to achieve this in SharePoint Online, so i was wondering if its possible to achieve this in SharePoint 2019 On Premise? Or is it simply not possible here either?

 You may need to disable loopback check on the server - since we don't have server access on SharePoint online, that environment can't be modified in this way. This article describes two methods - disabling loopback check is less recommended in terms of security, but may be faster to verify that this is the root cause of the issue: https://support.microsoft.com/en-us/help/926642/error-message-when-you-try-to-access-a-server-locally-by-using-its-fqd

So i just tried to disable it on the machine where SharePoint 2019 server is installed, but no luck. Still getting the same error, do you have any other suggestions?

You've checked the ULS logs for any additional info?

I tried checking the ULS Logs, but weirdly i cant even find the error in ULS anymore.. Tried to reset the monitoring settings to default but no luck there. Have tried with the ULS program and with PowerShell scripts directly, nothing. The ULS program does show up several other error messages so it is logging errors. It does have the same Log-ID though, so might be the samme error as before (Unautorized)