As my BL-Touches have started to age I have noticed this happening from time to time, they start blinking red and the printer stalls before starting the print.
If this has happened to you as well it is most likely the same issue, the pin/probe is stuck inside the BL-Touch.
Fortunately, the fix for this is very easy and quick. I simply take my plyers and force the probe in and out a few times. Be careful not to snip it. That’s it.
My guess is that there is some dust stuck in the device that causes this to happen but so far there have been months between it happening and the fix is so quick that I have not bothered to open it up and clean it.
Hope this was helpful to someone