We have been using nextcloud ios app for a couple of years and we also use goodnotes. When you do a export from Goodnotes to a 3rd party app, it shows the name that the pdf created will use. then it opens up Nextcloud and it shows the folder to create the pdf in. Nextcloud use to retain the name that goodnotes used as a export, and now it just uses the Date and time. This is the same thing it does when you use the box with a up arrow to send images to nextcloud.
Was there a recent code change in the IOS app?
we are running the 2.25.3 version which looks to be updated 2 weeks ago.