Gear selection switching to parking when AC unit is on

[YuriM]

Hi all. I have a weird issue with my Mercedes w212 E350 (2010), where when it's hot outside and AC unit is on, gears won't go into D or R, it would kick back to parking. When AC unit is off, it seems to go without issues, mostly, but sometimes even that would not help. Again, happens only when it's very warm outside. When I took it to dealer and then other garage, by the time I got there it was gone, and they couldn't find any faults, or didn't care to find. Hope someone can advise. Thanks in advance.