Delay in presenting caller-id, only in the last month?

[#1]

I have my DECT Gigaset S810 programmed with different ringtones for different callers, of course triggered by the caller-id.
For years that has worked flawlessly. The phone rings with the programmed ringtone depending on who is calling.
A month or so ago, all calls have started to ring with the generic ringtone and only after a secodn or two, switched to a custom ringtone.
As far as I can see, that's because I am not seeing the incoming caller-id presented immediately..
Absolutely nothing has changed at my end. Is there anything Plusnet could have changed to cause a delay in presentatiopn of caller-id?
Many thanks.
Mark

[#2]

Have you tried calling your phone and watching the display to check how soon the calling number is displayed (probably best to try multiple times)?
It could be that the information is coming through in a timely manner but that your phone is taking more time than before to look the number up in its stored directory.  I would imagine it has to compare and identify the number against that stored information before it can apply the desired ringtone.

[#3]

Thanks for your reply - that's a good thought but not the case here I think as I've only got 5 names in my directory.
I did what you suggested and that gave me the clue.
The Gigaset has a feature to mute the ring on CLID Withheld calls. I guess that to achieve that it has to not ring untill it has received and processed CLID. At which time it can either not ring if Withheld, custom ring or generic ring.
I had forgotten that I'd switched that feature off and suspect that caused it to ring immediatelly with a generic tone and switch to the custom tone after CLID processing. I would call that a minor bug and will notify Gigaset.
Thanks for making me think it through logically.
Mark

[#4]

I've been with PN's phone service around a month, and my Gigaclear DECT phone responds first by very briefly showing caller's number & then the name from the Directory, if it's in there.