I made two quick updates to one of my Survey123 forms (I've made many updates to it and had no problems prior to this) about a week ago and since then I've been unable to publish the updated version. When I click on the Publish button in Connect, it successfully goes through Checking Feature Service and then brings up a dialog box letting me know the survey has already been published and that it sees I'm trying to add a field not already present. I click on the button to "Add the following fields when publishing" and then click on "Publish Survey". At that point it just hangs and nothing happens.
I found a post where someone had a similar issue and you said to go to the Survey123 Connect settings and turn on logging. I did so and am attaching the log file. That post also asked the user if the form item was removed or changed location. I did notice at some point that my FS and form item were not in the Survey123 folder and moved it back there. I'm pretty sure I've successfully published updates since then. On the off chance I was mis-remembering, I put them back and tested it again but it still hung.