Hi @lonacunn Welcome!
I recommend duplicating that same workflow and try it with a new flow file, although if that does not work i recommend either restarting your current instance or upgrade/downgrade to the nearest stable release this has helped a lot of people who faced this issue earlier.
Hey since its happening on two completely separate instances right after the upgrade thats almost certainly a regression in 2.10.4, not something on your end. i would roll back to 2.10.3 for now and file a bug on the n8n GitHub repo if there isnt one already, the fact that its reproducible across multiple instances makes it a solid bug report. Cheers