Check Valve - Broke Air Pump

So my Grobo pump went out today. The unit vibrates, but when I pulled the hose out, it’s on, with no air coming out. Swapping to external pump it works fine.

I noticed when I took the hose off internal Grobo air pump - there was water that came out - I did have power outage and suspect this might have been the culprit

Check Valves prevent this - Wonder why the Grobo air pumps don’t have them ?

I put one on my external pump, and submitted support ticket. But looks like I can join the crowd of broken air pumps.