Is Tank Spotting TOTALLY bugged?

[A Canadian Cat]

Didn't you look at the picture?

Snark ignored - moving on...

Here's another frustrating example:

...

"Reverse Slope"?

And as minor problem: my tank was sitting there around 10 minutes with a narrow vehicle cover arc and couldn't get a spot on that tank in the open; although it had received contact markers prior (which even should help spotting).

Yes, trees are fully switched on.

OK that does seem frustrating that it took so long to spot the enemy.  

Just a couple of notes:
1) a narrow cover arc will not help with spotting.  All cover arcs do is tell the unit where they are allowed to engage the enemy.  
2) the message on the target tool is explainable: the enemy vehicle is in a reverse slope position which means at least its wheels are below an obstruction between your tank and the enemy and your tank is partial hull down probably because of the same obstruction.

I am not sure how much of the enemy tank yours can see from its position.  I take it this is from the same game files that you shared with me earlier.  Which I will get to eventually but I am pretty busy and will only get there once I have my work for [REDACTED] sorted and get fully caught up on my PBEM games.  Honestly it could easily by a month before I do.