It's a difficult time to be experimenting so props to you for sticking with it!
My suggestion would be to use different wallets for different things. Non-custodial wallets don't integrate easily with nostr clients. For this use I would suggest a custodial wallet. I've been using alby and it just works. Another great option is primal (assuming you want to use their client).
As far as non-custodial wallets go, you're trying the best (easy-ish) options available. If reliability is what you value you most, try phoenix. It's more expensive than mutiny but it works instantly every time.
Keep stacking knowledge and maybe you'll decide that one day hosting your own node is worth it.