We are in a process of migration from Claim-less SharePoint 2013 to SharePoint 2019 with Claims. Unfortunately, we need to use InfoPath for the time being.

Initial form for K2 process is browser enabled InfoPath form, uploaded on SharePoint 2019 Web App. Form was transferred from SharePoint 2013 Web App, which had Windows authentication enabled (we didn’t use Claims on that site).

After fixing the issue with K2 process Originator being shown as K2:NT AUTHORITYIUSR (really appreciate help received here https://community.nintex.com/t5/K2-Five-Forum/Process-Originator-showing-K2-NT-AUTHORITY-IUSR-instead-of-user/td-p/207025), now I get SharePoint 2019 Web application App pool account displayed as process Originator. I would really need to get user who filled out the form displayed as process Originator (as in pre-Claims version).

Can anybody help me with this? Thank you in advance!