TL;DR Error 2564 only shows up at layer switch after restart while printing at 100% speed. If you lower your speed to 50% the error never appears again. If you want to read my whole story, read it below.
I am trying to get a print of a tabletop game for my school and I have to use the whole bed to print the game however there is a problem which is Error 2564 
By the way, I mentioned âwhole bedâ part specifically because I donât get the error if I print something in the middle areas.
Anyway, there was no problem until I hit the fourth layer during printing, everything was going fine. Then the Error 2564 came and I restarted the machine and resumed the print. It heated back up to 230 and continued printing at 20% speed. It finished the layer it got stopped by the error and when it switched to the next layer the temperature would drop without ever increasing, and when it gets to 220, it gives the error again.
So, replacing the hotend just around 2 weeks ago, I believed it had to be software related.
I waited to see if the Error 2564 would come again on the next layer switch and it came again. So I restarted again BUT this time when it started to go back to 220 degrees I changed the temperature manually to 231 degrees and magically it started to rise up to 231 immediately 
So I waited again to see if it drops or not and again it started to go towards 220 degrees and this time I put the temperature to 229 and it started to go up again a bit but this time it quickly dropped down to 220 and machine stopped. So I thought it had to something else but I saw that it wasnât hardware related because the temperature went up even though it was bound to give me an error code if I didnât interfere.
Then I thought to myself that it doesnât give the error when I restart but when it changes layers so what changes when it switches to a new layer? And the answer is Print Speed. The machine automatically puts the speed to 20% when you restart it until it finishes a layer and then it goes back to 100% and at that moment the temperature starts to drop.
Now I started tracking the speed in Creality Print 5.1 app and when it increased the speed to 100%, the temperature immediately started to drop. I decreased the speed to 80% and it was still dropping. And at that time, I decreased it to 50% and, voila, the speed went back up to 230 degrees and stayed there. As I am writing this right now, it is staying at constant 230 degrees for 30 minutes without a single issue.
So, my question is, after all these things, is it really a hardware issue as most videos/posts/guides say or is it software/firmware issue seeing that I was able to bypass the error with a simple speed decrease? I am really lost at this point, I have been using this 3D printer for a year now and I know how it works, I tinkered with it a lot this last 2 months and I have been printing almost everyday for school projects and needs. There is also the issue of machine wear and tear for using it every day, I know that, but with a new hotend this shouldnât be an issue. We donât get enough funding as well and I donât want to put more expenses unless it is totally going to fix the problems.
Do you have any permanent solution for this apart from printing everything at 100 mm/s speed from now on or should I change the hotend again?
Edit: Did some more testing on this. If you increase the speed directly to 70% from 50%, the temperature drops suddenly. However, if you raise the speed in 5% incrementals (50% 
55% 60% 65% 70%) you can print at 70% speed without any problem. At 75% speed the temperature drops so slowly but it doesnât increase at all so I would say 70% is the sweet spot on my case. Hope this at least help someone suffering from same issue if it is really fixable by some code/software tweaks.