Signal dropping out on RBR10 both wifi and powerline plugs

Hi,

Need help as have tried everything that have been able to find and tried everything other have but we're still having drop out issues.

The story so far..

We originally had BT internet but got offered a good deal from virgin with a lot bigger line (BT was 20mb vs 110mb with Virgin) and me being greedy switched to it and have regretted it since. We were running a BT router originally with powerline plugs to use with our work laptops and although the speed wasn't blistering there was never any issues with signal.
When we got Virgin Media installed in November of last year, we had issues off the bat but Virgin have fixed all external issues and are providing a solid 110mbps to the property (confirmed via ping logger).
We tried using the Virgin media router but it was terrible and signal was lost a lot regularly. After discussions with friends we invested in the Orbi RBR10 with 2 satellites RBS10 and have switched the VM router to Modem mode and have been using the Orbi as our router since.
The problem is that we are still having intermittent issues with internet supply to our work laptops which is having a detrimental impact on working and meetings. This was happening regularly when using the plugs so we tried running them off just wifi and we are having the same issue. I've noted that the plugs throttle the speed to about 50mb and we're ok with that but its the drop outs that are making the issue untenable. When running the laptops on wifi it drops out but seems to reconnect to the internet a lot quicker.

The location of our ORBI is set due to the VM router but i have sited the powerline plug around the room to a plug with no toher sockets to reduce possible interference to the powerlines but the issue still stands. Don't think this is the issues with the powerline plugs tho as the wifi drops out at same time 

So to summarise...
Detail:
Virgin Media Hub v3.0 set to run in modem mode
Orbi model RBR10 with two RBS10 satellites
Orbi Firmware version (Router & Satellites) : v2.3.6.18
Orbi satellites are all showing up as good connection with 5GHz

The 2.4GHz channel has been set to 8 based on review of best available APs
Connections multiple tablets/laptops/phones (11 devices in total but not all being used at same time)
Internet speeds
Powerline plugs are Devolo dLAN 500 AVplus
I've checked internet speeds in all areas of house and when it is working i am getting about 110mbps

Issue:
Signal not consistent and is dropping out intermittently
Signal dropping out (both powerlines and Wi-Fi)

Issues are on more than one device

Help required:
Advice required on how:
- locate the problem
- advice on system setup
- ideas on how to grow the hair back i've pulled out

Any help at all would be gratefully appreciated.

Many thanks