Some relays are paid to write (and some are paid to read as well), so that could be an issue with a failure to write, depending on the relay. Do you know which one it was?

Relay selection can play a pretty vital role to your nostr experience, in addition to client selection.

As far as clients, I personally use Damus (iOS), but amethyst is great on android. I don’t use too many web clients so maybe some others will have some suggestions if you’re looking for recommendations there.