No, although I was weirdly unable to get a DNS lookup on usps.com for about an hour earlier today. No other DNS or network issues, I've been in all day, and all outbound traffic on the LAN goes through an exit node chosen from the global list at random every 6-8 hours.
When I have any Mullvad issues, I manually bounce to a different exit node and it has never failed to correct the issue, so far.