You are welcome...here is my deduction:
33 is overheat code.
The temp rise which is normally operating desig temp is 30-60.
You running temp is 30- which means you are certainly not overheating.
This eliminates dirty blowers, gas pressure, duct, dirty ac etc..
If any of those were a factor the temp rise would be 60+.
This leaves us with 2 options....
1- a weak limit switch. It trips at lower temps than it is supposed to.
2 A bad circuit board. Turns blower off at random.
I apologize I did not mention a weak limit. The problem with this unit is I changed so many boards I aometimes neglect the other potential answers.
It may be cost effective to replace the limit first as a move toward a solution.