Same here. Just tried again. Didn’t work. It’s quite frustrating this bug still exists at this point. Numerous updates have happened and it’s still doing this.
I am seeing the same issue on my device as well. Even though they are added in my contacts, it shows that they are not part of my contacts. Adding them will only work temporarily and then go back to not being added.
This bug is related to iOS only and has nothing to do with Android. If some user is showing his phone number, and you don't have them in your contacts, it's correct that you see the phone number instead of their name.