Regular Speed drops

Hi recently have been regularly been getting bad speed  drops.  Should be getting over 100Mbps but drops to under 10Mbps.  

Current BQM test: https://www.thinkbroadband.com/broadband/monitoring/quality/share/67eeecbf2325f1f639d2409a66c24ba67942a800-05-11-2025

Makes internet barely usable  until it recovers.  Tried turning router off and back on,  the network  diagnoses in router is obsessed with wifi speed even though connected via ethernet.  I am getting to the point of considering leaving Virgin after several years because of the service now and quite frankly being charged a  lot more for lesser service than new users