posted by jeffrey562 reddit this worked for me ty Entering the CS and then leaving will give you frame spikes every 2 seconds on the character you entered the CS with. Moreover, the spikes will persist into the log-in/world/channel screens persist after relogging persist after restarting Maple if you log onto any affected character
Here's a fix: There's a chat channel key-bind. Use it and join a chat channel, then you'll be good to go. The chat channels can take a while (possibly hours) to appear.
An alliance member (Mae) contacted me via Discord and asked me to forward this information for him.
Discussion about what might be the source of the problem is below. In view of the fix, the speculation that the issue is with repeatedly attempting to connect to chat channels seems highly plausible.
CS will disconnect you from chat channels and then you get screwed because chat channels will attempt to auto reconnect forever.