Unfortunately dude I think this is all one big coincidence. It makes no difference whether you are on 100mbit or 200mbits. You are using the same superhub which will be bonded and using the same channels to send your traffic over as you was before. The only thing which would have changed when you got "upgraded" is that a new config file would have been sent down to the shub "telling it" it is now allowed to do 200mbits and not 100mbits. In laymen's terms for you, you are still driving down the same road in the same and all I have done is remove the 30mph speed limit and you are now allowed to drive at the national limit.
I would honestly give it a day or two and see what happens. It is possible there has been an area fault over the weekend/bank holiday and they are waiting for the guys to get back to work tomorrow to address it. In the meantime there are 3 things you can do going forward should you problems persist (and they will do even if you downgrade to 100mbits).
Firstly you can run a speed test (or several) and see what sort of speeds you are getting now:
Secondly you can take a look at your router settings out of curiosity and see if the new config has dropped down (especially if you aren't getting anywhere near 200mbits in the speedtest which you have just done) and look at the power levels on your channels etc. Poor power levels on the upstream can cause connectivity issues and poor levels on the downstream can give you speed issues:
Thirdly if you are still experiencing issues then you also need to make one of these for diagnostic purposes. If all is well it should look like this:
and if not it will look something like this with some chunky red in the middle for artistic effect:
If you do come back here and want some more advice/help then please make sure you post your speed test result, your power levels for the upstream and downstream, your network log and setup and TBB monitor and share the live graph so we can take a look at it.