Ok this post convinced me to switch back to Core:

Removing OP_return limits seems like a huge mistake

Removing OP_return limits seems like a huge mistake

Then follow the steps here but do it for core instead of knots:

bc-guide

How to migrate from Core to Knots on Umbrel.

Bitcoin guide

And run this command instead: cd umbrel/app-data/ && sudo rm -rf bitcoin/data/ && sudo mv bitcoin-knots/data/ bitcoin/ && sudo rm -f bitcoin/data/app/bitcoin-config.json