Hey everyone. I have a little more information about this, I have some inside from the dealer.
First of all, I had previous Golf 7.5 with the same VW Keyless System and no issue for 5 years! No matter what the weather is or how dirty is the car. Probably I've never pressed the unlock button on the keyfob except to open the car far from it.
Now I am having
Cupra Leon ST with the same issue, mentioned in previous posts.
VW Group changed manufacturer for the keyless sensor and now we all have issues opening the car with a hand (including VW ID.3 and maybe other brands/models).
The
problem is due to electrical measurements caused by salt or other dirties. Even It's enough for the dust to stop working. You can check this by washing your car with clean water under pressure. It's should work until the hand is dirty again (I tested it when it was -10 degrees). Don't try to clean with a napkin, doesn't
help
The latest news says that a software update addressing this
problem should come this February, but it's unknown if it will be OTA or service visit.
Talk to your dealers, this is a 100% guarantee case.