[Defender] Defender Plugin Blacklist Monitor Errors

I am having issues with the Blacklist Monitor in the Defender plugin. It seems that it will NOT initialise correctly. Sometimes it just goes round in circles when I attempt to activate it and sometimes I get the message (see attachment) this is not isolated to this domain alone and the same is happening on the following domains as well:

bricknblocks.uk
nploy.io
oakwoodmeadows.co.uk

I have yet to chaeck all my other domains.