On one of my British cars if not used frequently the speedo needle will stick to the post at the zero position, One tap and it is free.
My 120´s speedo does exactly the same😅
I have come across this a few times. The cause was that the stop peg for the needle is covered with a tiny piece of black rubber tube. Over time the rubber perished and became tacky. I removed the rubber and the problem was solved.
Nowadays I replace the rubber with a similar piece of plastic tubing. I doubt you can buy this size of miniature tubing but what I do is retrieve the ear bud kits the children have thrown out, cut a piece and draw the wires out. The difficulty with this is finding black as most are white. The main reason for having the pin covered in black is to make it ‘invisible’.
I have also found these cables to be a useful replacement for the bulb power supply in trafficators. Because they are multi-stranded, they are built to take multiple bending, which is ideal for the repeated 90° swing of the arm.