No flashing light 1571 button.

[#1]

We use 2 BT Decor phones because they have hearing aid loops, they have 1571 buttons and we have the Plusnet 1571 service which does the intermittent dial tone if a message as been left for us.
With our previous suppliers the 1571 would flash so that one would notice a message had been left earlier than picking the hand set up or pressing the button just in case.
With Plusnet the button does not flash, is this usual with Plusnet?
If Plusnet not sending the signal or what ever could they consider its addition?

[#2]

This has been discussed before on the forum - there was an issue with another customer - I'll try and locate the post.
*edit - do a search for 1571 flashing and you'll find some more info.

[#3]

This is the one .
I retired from BT in 1999, before liberalisation really took off, but as I understand it, one surely has to be connected to a System X or Y exchange, no matter who you pay rental to. Ergo, the stuttered dial tone should be available.  If not, there's a fault - isn't there?
If anyone knows different - please correct me.

[#4]

Correct me if I'm wrong, but given that the dial tone (normal or message waiting) is generated by the line kit, surely it matters not who provides the phone service?

[#5]

Until recently I would have agreed, Townman, but see this thread, where the dial tone is not interrupted - seemingly because the OP migrated from TalkTalk.
In dnpark38 's case, it seems he is getting the special dial tone, but it's not triggering the lights on his phones.
On page 3 of SIN 350,- BT Public Switched Telephone Network (PSTN): Network Tones And Announcements - it appears that the Special Proceed Indication (Interrupted Dial Tone) comes in two varieties. In one case only one tone is interrupted, in the other case it's both.
Maybe the phones need the second variety.