Luca
I can reproduce the problem.
We are actually working on THERM 8.1, which will have the same functionality but some other changes.
We will make sure that this bug is fixed in that version, which will hopefully be available as a Beta version for testing in a month or so.
Sorry that this probably means you won't be able to use THERM 8.0 for your modeling needs.
Thank you for testing and providing this valuable feedback. We understand it can be very frustrating, but we appreciate the feedback.
Robin