Not that I have tested out or can prove. Just that in all my countless hundreds of hours playing these games, the only time I thought there was something seriously wrong with tank spotting was when a JpzIV sitting on a location with full view over a big field let a whole platoon of Shermans approach from 1500m till they were literally driving past. Weather was flurries, but that didn't stop other units from spotting the tanks.
Anyway, in this case, it's not Jpzs so it's off topic.
I don't see anything in these screenshots that suggest why those TDs should not spot a firing Sherman. Nothing wrong with the tactics either.
@SDG when you select one of the TDs and draw a target line to the Sherman, does it show you have LOF? Sometimes the game denies LOF for no apparent reason.
The low hedge in front of the TDs shouldn't block line of fire, especially since the target is elevated.