[coverclock]

I too have tried to use a USB power bank as a kind of DIY UPS to power a Raspberry Pi SBC. What I learned - which may be unrelated to your experience - is that all of the several power banks I tried can be either charging, or powering a device, but not both at the same time. So my Raspberry Pi would run until the power bank got low, then the power bank would cut power to the Pi and charge itself, then power the Raspberry Pi up again. I had to buy a power bank specifically advertised as a USB UPS; that worked fine. The normal power bank seems to be designed to charge a battery powered device like a mobile phone (whose own battery can be thought of as a kind of UPS for the device), but not a device that requires continuous power (like the Pi).

[KolenCh]

Which one did you get? I got a Zendure specifically for this purpose, but I find it the hard way that when it switch between battery power to wall power, it will momentarily lose power for a sec, resulting in a reboot