Can I switch Windows Defender back on temporarily if I exit Trend Micro Max Security?

My son’s new laptop (when connected via his school’s network and web filtering protocols), has extremely slow internet speed/connection while TM Maximum Security is running.  When TMMS is switched off (exited), internet speed/connection at school is normal again. His laptop’s internet  speed and connectivity at home (outside the school’s network) with TMMS running has no issues.  Note that all exception settings have been applied within TMMS dashboard to ensure approved urls/sites can be accessed so this is not a variable or factor.  I suspect the school’s web filtering protocols are clashing and/or causing a dual web filtering scenario which is causing the speed and connectivity issues on his laptop while at school.  As a work around, my son would like to exit TMMS during school hours and simply turn on the built-in Windows Defender on his laptop’s Windows 10 (Home) system to offer him antivirus and fraudulent website protection while he uses the school’s internet.  However, once we exit (NOT install) from TMMS, there does not appear to be an option in the Windows Security Settings that allows us to switch Windows Defender back on.  The only option offered in his laptop’s Windows Security Settings is to turn TMMS back on.  Any idea if or how the Windows Security Settings can be forced to display both Windows Defender and TMMS as options that the user can select from and turn each on/off as required?  It is almost as if by installing TMMS, the software has blocked Windows Defender from being displayed as a choice/option in the Windows Security Settings.  Any ideas about how to force Windows Security Settings to display Windows Defender as an antivirus option if TMMS is exited?  Also, when pressing “exit” on the TMMS dashboard, does TMMS truly suspend running or is it running in the background and that’s perhaps why Windows Security Settings won’t offer Windows Defender as an option?  Or has TMMS disabled Windows Defender so deeply in the Windows 10 OS that it cannot easily be activated when TMMS is installed?  I really don’t want to uninstall TMMS as I like the product better than Windows Defender, however, sending my son to school with no AV software turned on just so he can actually access school web resources on their network is not an option I want to continue doing.  At this stage, without a solution from the TM tech support, I will have no choice but to uninstall TMMS from his laptop and go back to the default Windows Defender on my son’s laptop so that his learning is not disrupted any longer.  TM Tech Support, please please please provide a viable solution to this problem ASAP (I have called two TM techs in the past week and neither could answer these questions and neither knew what to do to fix the issue).