Thank you for the tips. I will clean it more.
I found another thread with the photos out of Fluke 187.
https://www.eevblog.com/forum/testgear/fluke-187/Photo# 187_14.JPG with ICs is from identical PSB. The same 3 pins are connected there. I believe I may conclude that this is OK then.
Is faulty of RMS converter common issue for fluke multimeters?
Update: I thoroughly cleaned all ICs pins but it did not fix the issue. It seems like I will for other solutions.
I called to Fluke and they stated that this device can be repaired under warranty if none damage from neglect, misuse, contamination, alteration, accident or abnormal conditions of operation or handling, including overvoltage failures caused by use outside the DMMs specified rating, or normal wear and tear of mechanical components. They suggested to send multimeter to them and they will let me know if they can fix it for free.
I am wondering if someone had experience dealing with Fluke customer service and what are the chances the multimeter will be repaired for free. Thank you!