It’s amazing how COVID-19 has derailed the year. Back in February I posted a question about not being able to add files to an item (see https://forum.omeka.org/t/cant-add-new-files-to-an-item/10573).
Following guidance from jflatnes, I increased max_input_vars in the php.ini file and that resolved the issue. I just wanted to post a follow-up so others may benefit.
Cheers.