ServiceNow stopped updating additional comment from Guest replied Email

[bbf35621]

Hello devs,

Last Friday, I set up a Case updated comment notification that sends out to the watch list, consumer, and is assigned to. I added my personal email to the watch list, which is a guest. Whoever made a comment in an additional comment, I got that notification in my personal email. Then I reply to that notification and the ServiceNow case updates my reply in the additional comment case ticket. Everything looks good until I test it again yesterday and today, ServiceNow has stopped updating additional comments from the Guest replied email. Currently, it only works for SN users. Does anyone know why that happened and where I should troubleshoot? I haven't changed anything, and I have tried adding ACL write in the Case comment to allow Guest, but it is not working.

Here is a sample screenshot of the last time it was working,

[Ankur Bawiskar]

@bbf35621 

the user who is replying should have write access to that record and also the comments field

Did you check that user is satisfying these ACLs?

Any recently added ACL is blocking?

If my response helped please mark it correct and close the thread so that it benefits future readers.

[bbf35621]

There is no ACL block. I have replied to other of my findings below. The result is that it was unable to locate the Case sys ID with sys ID to append the reply to the additional comment. However, that case sys ID does exist, and it is the same one that I tested last Friday. I am not sure why.