I have a modern Desktop and an old laptop. Both are on Windows 10 version 1709. Both have Defender as a/v and Malwarebytes Premium as anti malware.
The Desktop is fine running both. Today on the laptop I noticed that MBAM was showing in the action centre as the only anti virus. Defender would not switch on. Dr Google suggested that in MBAM settings ,under Windows action centre, I click on the second option down , not the first as on the desktop. Desktop option says "Let MBAM apply the best action centre settings based on your settings" whereas to get Defender going on the laptop I had to apply the second setting down which says" Never register MBAM in the action centre"
Will keep an eye on it but I would welcome comments from MBAM / Defender users
Having updated MBAM to new version, Defender works even with the MBAM option 1 selected. Now have a problem with the latest W 10 update that fails to install on the old laptop. Will try the troubleshooter. Maybe connected with intel issues? Otherwise will try with MBAM disabled as Defender is said to be compatible with the update. Worked on desktop with MBAM running , though, after Intel issues solved.