A10 indicates a fault in the heater circuit.
Heater, wiring or main control board are the likely suspects.
If it's intermittent, then the control board is the most likely.
Are you using rinse aid and all in one tablets?
Have you changed the type of tablet?
Have you changed the brand of rinse aid?
OK, thanks for that.
You are double dosing on rinse aid, and always have been if you are using all in 1 tablets.
I did ask questions about the brand of rinse aid and the type of tablet.
You haven't actually answered these, unless "I am not doing anything different" is the answer to the questions.
Turn the rinse aid down to it's minimum.
You may be getting a poor wash if the machine isn't heating properly.
The top spray arm will wobble a little, under pressure it should be fine and turning.
Is the machine heating properly?
Machine heats OK may even be too hot
rinse aid/ tablet brand have always been value but the performance lately has altered since the A10 display
As previously advised, A10 is a fault in the heating circuit.
If the water is getting too hot then this would suggest the problem is with the sensor attached to the main control board.
Sorry, I've no checks for this nor is there a way to prove this on a remote diagnosis.
I'll opt out of the question and open it to all experts again.
See if anyone has anything they can add.
Good luck with it.