Delay in processing PIP Review

Hi Panel,
I got my PIP review forms last August and with help completed them in time and returned them in early September’23. My award ran out in April 29th ‘24. I get a letter a week prior to this extending the award until April 29th ‘25 giving themselves another year to process my PIP review. I have a set of chronic, deteriorating health conditions/diseases for which there is no cure and as I have deteriorated further I’m hoping that my review will increase the Daily Living section to the higher level (currently standard) and maintain my Mobility section at the higher level.
My question is - is it normal practice for DWP to extend these reviews for such a long time? My initial PIP application took so long that my 3 year award had under 2 years to run by the time that I got their decision. This was during the pandemic and I had a telephone assessment.
I submitted a full set of information for the review - consultants letters, operations/procedures done etc etc as recommended on this site. I couldn’t have done it (or my original application) without my daughter doing the typing, photocopying and indexing etc or the excellent B&W Guides. I should have applied for DLA over 20 years ago but each time that I got the forms I was overwhelmed by the amount of information required and got timed out and abandoned the attempt the 2 times that I got the forms. I’m sure that many folk have found themselves in the same situation.
Many thanks,
Claire.