Deactivated TMs in several Projects: GroupShare 2017

We had serveral issues with deactivated Server TMs in current projects. The project is set up without project TM, so our translators write directly into the master TM on the server. Unfortunately some translators experienced that the server TM was automaticaly deactived during the translation process. Their translation could not be stored in the TM and could not be re-used by their colleagues.

Do you have an idea how we could prevent this issues?