I have a raspberry pi 4 running Ubuntu server 18.04. I usually SSH into it and reboot the system. However, I noticed that some times the pi does not successfully boot up again after shutdown so I have to go and manually plug it off then plug it on again. The pi is outdoors and it is kind of hot outside (around 57 C). I have other pi's indoors and I could not replicate the problem with them which leads me to think it is a temperature issue. Has anyone experienced this before? I can't have the raspberry pi not rebooting by itself this needs to be fixed.