As long as they're in sync and continue to update the backup side, you probably don't care those errors in "get sys ha status". I noticed "mondev" down on the standby(?) side as well, which you must have disconnected too. As long as one link is up for session sync, you should be fine. Just make sure new changes get copied over automatically. The particular config mismatch you found likely had some illegal component on the standby side, so when it tried to fix it by copying from the master it errored out. So it had to be removed first then it could be copied.
I've seen it on our a-p HA clusters time to time and sometimes the standby needs to be rebooted first to get it copied properly. Even with our 6.0.10, this happens and seem to be one of those "readers-writers problems". When it happens, you need to check checksums to isolate the problem config and fix it one way or the other like you just did. The last resort is to default the standby and let it re-sync from scratch.