Looks like it’s started as a service on boot-up.
I’d modify the script to also ping 188.8.131.52 and 184.108.40.206, and something local in the network, such as a printer that is always on, to prevent endless loop rebooting when the ISP is “having technical difficulties”.
Only when the Pi is also not finding the local network, then do a reboot.
The same script and service could be placed in a Linux based router, assuming the router doesn’t lock up in a manner that prevents other tasks from executing.
This is also a potential problem with the reboot script in the PiAware - if it is completely locked up, it needs an external supervisory system that can perform a hardware reset to force a reboot, much like a long hold power button kind of reboot.
This is where a separate Raspberry Pi fitted with a relay hat that switches the power to the bridge router and the PiAware, separately, can do a power-cycle reboot of either device that it determines is not responding, modified by whether or not other “always on” devices in that branch of the network, such as printers, can be pinged.