Router not resetting IP Profile

[#1]

For the second time now my IP profile is not being reset by my router. A BT Performance test this morning shows my IP Profile as 2.5 but I am downloading at a 2.0 IP Profile speed. Last time this happened a few weeks ago PN told me that my IP profile was 2.5 but I was downloading at 2.0 profile speed.
I had to reboot the router for the speed to change. This is only a recent occurrence as when my profile increased before it was immediately acknowledged and changed automatically. Now it seems I have to reboot the router for the change to happen. When the profile drops for example from  a reset to within a 2Mb profile the change is immediate but now not so when it increases.
Any ideas as to why this is now happening?

[#2]

I have just gone into my router and "disconnected" then "connected" and this has changed my speed, rather than rebooting. I still do not know why i have to this as it was always automatically done.

[#3]

If you've rebooted the router that should pick up the new profile.
I'd like to check it again if the issue happens again.

[#4]

I thought this should be a known issue - sometimes when the Plusnet IP profile changes, your PPP session is not disconnected, so the new profile does not take effect, until you manually disconnect or reconnect, or get disconnected for any other reason.