GoToAssist ServiceDesk scanning Test Phishing email attachements and causing false clicks

Regards to GTA ServiceDesk community;
We're a small MSP with multiple clients. We've been using GTA ServiceDesk for years; we're mostly happy with it.
Some of our clients use KnowBe4.com security training service that includes test phishing email campaigns.
The last couple of months, we noticed that if an end user forwards the test phishing email to our ServiceDesk as an attached message (or attaches the .eml file via the portal) - the false positive gets recorded, like the user clicked on the link/opened the attachement in the test phishing email. So, it seems like ServiceDesk is doing some sort of attachement links/fiele scanning, causing the problem in this particular scenario.  
Does anyone else have this problem?
Is there anything I could do on my end to to try to stop this form happening? 
I really doubt it; this feels like ServiceDesk support department issue...
Talking about that - does such a thing even exist? Does GoToAssist ServiceDesk Support have a phone  number I could reach them on? 
Thanks all!
Adi