Fixes were made to Fortinet driver. If you are on Linux, you can build current netxms server from master branch to test it on your devices - compilation docs are here: https://github.com/netxms/netxms/blob/master/CONTRIBUTING.md#%EF%B8%8F-development-setup
Or just wait for the release of v. 6.2
Or just wait for the release of v. 6.2