My 2019 Polo recently started intermittently showing a number of errors and warnings:

Tyre pressure sensor not available

ABS not available

Front assist not available

Parking sensors not available

The car would also momentarily feel underpowered and heavy to steer, before springing back again... But not necessarily at the same time as the errors showing.

I've taken it to a (very trusted) garage and they found a few issues. Firstly the battery voltage kept randomly dropping, but no problems found with the alternator. So I've got a new battery. They've also found a fault in one of the ABS sensors and a fault in the gearbox speed sensor. However, I've read that a faulty battery can present itself as electrical issues (ie the sensor warnings).

I don't want to have to take the car in more than once, but also don't want to spend a few hundred quid on jobs that might not need doing.

So my question is, what are the chances that the new battery alone would resolve the sensor issues, considering that fault codes have been found with the sensors? If it was a case of the battery causing the sensor issues, would fault codes still have been found? My family and I have used this garage for many years and find them to be very trustworthy, but I feel a bit unsure about this. It seems strange that the three issues would occur at the same time, especially in a car that's not even 5 years old yet. Any advice would be much appreciated!