Thanks. Somehow (I guess right-clicking) I found a way to report errors.
And the actual paragliding-take-off I have found on OSM and then using the 'long name' to find it in Windy (proper located): Mirador Lomo Molino. As long as I remember this name and not just El Tanque or Molino I'll be able to find that spot (and added it to my favorites).

At least after a quick look I couldn't find an option to report bugs in OSM. Do I have to report it as a new question in the forum there?

I was using the windy-app (IOS 13.2.3) several times within the last week here on Tenerife to decide where to go for paragliding. And stumbeled over two annoying errors:
These spots are found - but then located on other islands than Tenerife:

1. 'El Tanque, Santa Cruz de Tenerife, Spain' - located on La Palma
2. 'Playa Molino, Santa Cruz de Tenerife, Spain': located on La Gomera (I actually don't know where the beach is but as El Tanque is wrong, I tried the name of a restaurant and view-point where the actual take-off-place is nearby - and that this beach might be the one several hundred meters below.

Same here. We're a group of paragliders currently on Tenerife - and noticed differences within the results of a group member using a laptop and another one using the app (I don't know right now if IOS or Android)! Though not in temperature but wind-direction and/or -speed.