PPPoE Router disconnect/reconnect takes 5 - 6 mins?

[#1]

Hi,
Just after peace of mind on my FTTC connection.
I noticed with the supplied NetGear N150 and my upgraded NetGear N300 WNR2200 the action of selecting disconnect and then reconnect doesn't !, or at least go for a coffee and come back after 5 or 6 mins it does.
The same happens after a soft reboot.
Under a total house power failure like the meter swap out a few days ago, everything kicks and connects within a minute.  Obviously the vDSL modem went off as well that time.
Tried a TP Link TL-WR1043ND and it does the same...  Almost like there's a phantom PPP connection which has to time out first?
Sometimes unplugging the LAN cable to the vDSL seems to make it connect quicker, but maybe a coincidence as I'm getting worried fter 5 mins.
Do I have an underlying problem or is this delay the norm?
Pete

[#2]

It's normal for me using the PN supplied TG582n
I suspect there's some sort of timeout at PN if the PPP session doesn't close gracefully.

[#3]

Hi npr,
Thanks for letting me know it's not just me!
Strange as I was led to believe selecting disconnect was supposed to exit nicely but I'm having my doubts. 
Doesn't fill you with confidence whilst playing with a million extra settings on my TP Link and every re-boot takes 5 or 6 mins to reconnect
Cheers