What wifi router is it ? Someone with similar may have some insights.
Quality of Service... just do a search - lots of routers have the feature and basically it allows you to prioritise connectivity of certain devices, types of connection, activties etc.. to stop one thing sucking up the bandwidth. Look in the router settings and see if you can see anything - or it may be on the devices too - for example Dell's often have SmartByte running which AIUI does something similar.
To test speeds properly can you do it this way....
As you expect >100Mbps then connect a 1GB enabled computer/laptop, with up to date drivers, via a NEW and working Cat5e/6a ethernet cable, directly to the Hub which you have put into “modem mode” (https://www.virginmedia.com/help/virgin-media-hub-modem-mode
). This ensures that NO other devices are connected
Test speeds at https://speedtest.samknows.com/
- try on 2 different browsers.
If they are still low – boot your device into Windows safe+networking mode - to disable any potentially interfering software - and try again.
There are many posts on here (I have a list of ~30!) where QoS software, unknown/flaky software, old network card drivers, corrupted browsers, bad cables or other connected devices are limiting speeds on tests.
Report back what that gets.
I do not work for VM. My services: HD TV on VIP (+ Sky Sports & Movies & BT sport), x3 V6 boxes (1 wired, 1 WiFi, 1 on PA) Hub5 in modem mode with Apple Airport Extreme Router +2 Airport Express's. On 250Mbps, Talk Anytime Phone, x2 Mobile SIM only iPhones.