Twigs

So I'm new to 3D printing. I recently bought an Ender 5 plus, I have been having fun tuning the printer and making designs. When I print I have the printer connected to my computer. I use cura. I decided to print a tolerance test (my first long print) but my computer went into sleep mode while printing and the print stopped. I canceled print, cleaned up, changed sleep settings on my computer and started over. it printed for much longer but ended up randomly stopping again. computer did not sleep this time. So i cleaned up and started the same print again but from SD card but every time i print from the SD card the hot bed cools to ambient temperature after first few layers and the print comes loose and fails. the bed only cools when printing from SD, it stays hot for the whole print when printing from the computer . i can't figure it out!!