Only big prints fail

Hello,

recently I saw similar post and decided to write my own request for help/troubleshooting ideas.

I have Ender 3 v2 ( Motherboard version 4.2.2 ) for few years.

I keep my printer in self made ikea table closet for last year.

It was bumpy road. It always had issues. When you fix one, new immediately appears.

Sometimes I am thinking just to throw it away and buy something that works out of box, but I regret hours of troubleshooting and fixing that I already put into it.

Anyway, right now I almost can't finish any big prints. If its small one its fine. If print is 6+ hours it most likely fails. Not always, from time to time it works, but much more failed prints than finished

Problem:

Filament stops going thru the nozzle and printer keeps printing in the air. Extruder still tries to push it and grinds filament in it.

I dont think it is clogging as if I remove filament and put it again it works perfectly fine with next print.

I changed to metal extruder, I changed into new nozzle (multiple times) 0.4 size. Swapped to the Capricorn tube. Put yellow springs under the bed. And installed Marlin firmware with 9 points manual mesh (I failed to make BL touch to work with this printer this is why I use manual mesh, but this time lets not talk about that). I also performed cold and hot pulls.

Yesterday i took my printer out of closet and checked if all parts are in place tidy and everything how it should be by general integrity.

I can print a perfect calibration cube and occasionally get a decent other prints. But if print is taking long time to print if almost certain fails exact same way. And its happening for almost a year now.

In the post I mentioned I saw people talking about Sprite Extruder and now thinking maybe buy one. Logic behind that that if I change extruder and hotend maybe all potential faulty parts disappear?

Also I have Octoprint setup too.

I got suggestion to try printing with closet doors open to see if this is might be heat creep. Will check this hypothesis this later this evening.

Please if you have any ideas what I can else try, let me know.