Perhaps the 84 second burn overflowed the integer (2^6) and was caught by a 2^7s check (127s)
Why do you expect the Russian space program to be using new equipment after the antique show of an invasion in Ukraine?
Every country uses a combination of older and newer equipment in any war. The war propaganda wizards just try to make things like that look unique to Russia.
I would take what our jingoistic media and talking heads say with a very large pinch of salt. It’s quite disrespectful to Ukrainian soldiers to say they’ve been facing an “antique show of an invasion”, not to mention Russian engineers. Propaganda aside, both sides have fought hard in what has been a very modern war.