They don't expire. You just need to pay for updates after 3 yrs. I have the same SD card in my 16 since I received it in 2015. Still works fine. Same for my 2019.I was having the same issue and could not figure it out. The fix cost me £30.
You need to buy a new SD Navigation card as they expire after 3 yrs. This causes the system to keep crashing whilst driving.
Buy a new Nav SD card and all your problems will go away.
WORKED FOR ME!
More than likely the SD card was bad.