I’m having the same issue. I’m wondering if it might be WordPress 5.5 related. I tried updating the theme, disabling plugins, etc, no effect.
Update: We were able to fix it by adding the plugin Enable jQuery Migrate Helper
Investigated the WSOD issue further and isolated some code which we pulled (details in private messaging). There is a specific
request for reasons why he excerpted code fails and why it does not always consistently succeed or fail- we have models
working with the code present and models that fail with the code present Again specific details are in private messaging.