So we have 2 Service Desks Projects.
1 for IT and 1 for Finance.
Everyone in the company has access (as "customer") to the both of them.
But several people are now flagging when they get a notification email about a reply, they aren't always able to access the IT Service Desk.
For instance : there's a ticket where someone reports broken hardware. I take on the ticket, i add a colleague from Finance and a colleague from HR to it, and send a reply.
They both receive 2 emails (and slack etc) to let them know that I wrote something and mentioned them...
the first one is looking like this : 
When they click through, they get a "No Access" page.
The second one looks like this :

When they click the link from this one, they access the ticket etc...
Is this normal? Or did I misconfigure something ?
Thanks !