keyboard lag when using Messages only

I am using the magic keyboard AND the laptop keyboard and they both lag when i am using messages. It has been AT LEAST 6 months of this and I am just so fed up with it. There is no delay in typing when using email or other programs at the same time. It's quite strange and also quite frustrating as the computer is less than 2 years old, the keyboard is brand new and yeah I buy apple products because I expect them to perform well and last a long time and definitely not slow down mysteriously over time (wink wink).

Already went to accessibility and set to shortest acceptance delay, reset bluetooth, rebooted in safe mode, turned everything off, turned everything back on. What can I do?

Computer is: MacBook Pro (13-inch, 2019, Two Thunderbolt 3 ports) / 1.4 GHz Quad-Core Intel Core i5 / 16 GB 2133 MHz LPDDR3 / Intel Iris Plus Graphics 645 1536 MB