Thanks, Shytot and Steve. As a test, I filled up shell v-power yesterday and did some local and motorway drive. It could be placebo, but the car definitely felt responsive (especially gears 2 to 4) and the mileage shown in the short-term memory is over 7mpg more than last value. (28 vs 35).
I found a replacement sensor from Audipartsdirect and the replacement took only few mins thanks to the video here. I also received a response from Audi UK claiming that there are no defects with these sensors and that all warnings should be investigated by an Audi approved service center.
My Audi A5 2019 has started showing this error from yesterday. RAC guy confirmed the error but advised that my car is safer to drive. Showed him this forum and then quickly he changed his recommendation to drive only once back to home and get it fixed asap. It's a long 4 hour drive back home hopefully nothing bad should happen.