That zero RPM is the cause. If you have access to an Oscilloscope, probe the fan speed pin on the fan connection and you should see pulses. No pulses and it's either a bad fan unit or worse a motherboard failure. My test is something we can do in our shop but I can't guess what your background is and what test gear you have.
Without any gear you can try unplugging and plugging in the fan again and hope it was the connection. After that you try another fan.
Some PCs allow one to disable the fan speed error but this can also mean you lose the dynamic fan speed control.
My cooling fan was really noisy on HP 15-BA-113C laptop. I replaced it and everything seemed ok. After a few reboots the error code started to appear on startup. The fan is turning and moving a good volume of air. The Speed Fan program initially saw the fan and showed speeds and temps. Now the program displays zero rpm although the fan is turning. Is this a matter i need to resolve before causing harm to the laptop?

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