Hi Khaled,
I check that in the mIRC options / IRC / Logging, when the Strip codes option is enabled, if we use the character $chr(129) in custom themes for channel and query colors, then we notice that in the channel or query logs the character $chr(129) appears mixed in the middle of the logs.
I'm testing on the latest beta version 7.79.1717 but I've confirmed that this happens on previous versions as well.