I had this problem, too. I realized that the relays must be declared in your public Nostr profile. The clients I had been using only saved a private list of relays. I tried the Iris web client, and it lets you save relays publicly. Look for the purple button on this page: https://iris.to/settings/network
Discussion
Sir, I have been struggling with this since primal was available as a browser client. No one, including primal themselves were able to answer my question and give me the solution. It is so simple and given that I have been using Iris for a few months, makes me feel a bit stupid that I didn't figure out that making my relays public was the solution. I've never had that problem with any other client. I will honour the note I made a while ago(below) and thank you.
note1xj2v7f0uw2j95mpj3vx0e33rx7azrtk7dycge6yjt8cayajy6fjsls799m
Thank you! I’m glad I could help.
Tx that solved the problem!