I agree that it’s better to shut off the CO2 at night for reasons mentioned (I do), but others do successfully run it 24/7 and, apparently, the OP has been doing it all along without incident. This sounds like some kind of hardware failure.
Please describe your setup: regulator brand, single or dual stage (not gauge), solenoid and needle valve.
I wonder if the regulator is flaky......come to think of it one of the gauge (pressure to tank side) I just notice is not showing a 0 psi but I know it's not dispensing because I don't see any bubbles or any hissing when I remove the tube from the canister.
What is your high pressure gauge reading? It should be in the 600-800 psi area if just filled.
Did you follow correct startup procedure? This involves making sure the needle valve is open and low pressure gauge is off, then SLOWLY opening the CO2 cylinder valve until the high pressure gauge climbs to 600-800 PSI. Then SLOWLY open the low pressure gauge and, lastly, adjusting the needle valve. If too much pressure is suddenly introduced at any stage the valves can be damaged.
To test for damage (or leaks), do the startup procedure but, at each step, hold the pressure for about 6 hours before moving on to see if the valve at each step is functioning. Example, with the high pressure valve closed, open the CO2 cylinder then shut it off and see if the initial 600-800 psi holds. If it doesn’t, the valve at that point may be damaged. If it works, move on and do the same thing at the next step. Before deciding if a valve is damaged (if pressure doesn’t hold at a given step), use the soapy water leak test on the involved connections and around the gauges to make sure any pressure drop isn’t due to a leak at those places. This includes testing the solenoid by shutting it on and off and watching to see if pressure holds at stages before it and between it and the needle valve.
BTW: bps is not a good way to judge CO2 levels, but that’s a lesson for a later time, after you solve the hardware issue.