I actually like it when you have powerful options available in a wallet, presuming you understand them and know what you're doing. I can't say for me that I'd have any use for such a Sighash option that Sparrow offers in its UI. I also can't say that I understand them confidently.

Maybe it would be good to hide or disable them in UI, unless you turn on power-user mode in settings (makes life for programmer(s) less easy and surely there will be some to complain what is power-user worthy and what not.

So far presented details indicate to me that OP was in panic mode and didn't take the time to investigate the error messages and finally thoroughly check all settings before broadcasting transactions (the sloppiness involved likely due to perceived need to rush it).

It's not my intention to point fingers or blame him. Anybody interested in this particular issue should learn from the chain of bad events.

The mystery of the unknown target address remains that kicked OP out of smooth orbit.