TeamViewer 12 Host connectivity issues

I work for a software company and we use TeamViewer 12 Host to provide support to our customers.

Recently we've been experiencing alot of connectivity issues to the Host when trying to connect to our customers. The connection to the customer will show up as normal as an active connection for a few days, weeks, or months but will randomly appear in the "Offline" category and the only way to resolve the issue sto get TeamViewer un-installed/re-installed onto the customers server.

We've also noticed that the TeamViewer service and/or installation is completely gone off the customers server after a period of time.

What's causing the random disconnects to our Host client?