How long for the automated systems to drop the PPP session

[#1]

A bit of background
I had a resync in the early hours in the morning and the effect was for the sync speed to drop about 400kbps
Did a manual resync which brought it back up to 4192kbps
Plusnet profile dropped later that day to 3300kbps so I left it to sort itself out and after nearly 3 days it sorted itself out - so it seemed to work as it is now showing 3600kbps
HOWEVER speed tests still reflect the 3300kbps and the PPP session hasn't dropped.which it should have done when the profile changed
Is this a glitch or do the two events - change of Plusnet profile and PPP drop done by separate scripts at different times

[#2]

We've received the updated profile which then sends a script that initiates a PPP disconnection, this should happen within 10-15 minutes generally but in this case it's clear it's now not going to happen. So it's is two seperate scripts.
Not seen any others reporting this, a soft disconnect/connect will be the best way forward as it stands.

[#3]

have done and speeds increased as expected