Is this normal with dry-lining back boxes or is mine broken?

[mikehammer69]

It was them that made the round shower isolator ? They were great

And of course the ubiquitous bulkhead . Well , when they changed to a slotted screw

The quality shower isolator was actually crabtree now I recall

 

[SUNRAY]

I believe they were. designed to help with other non electrical standards. fire and sound they have like a. gel stuff inside them.

https://www.tlc-direct.co.uk/Products/FB4235.html?

OK...
I've used that pattern of PB box but not including the intumescent lining. As I mentioned before the metal 'blades' tend to wear the PB and become loose and eventually pull out with constant plugging.

EDIT: Not sure how my text was truncated.

 

[BS3036]

I use scolmore click range now and its made in the UK

"Scolmore’s Click range of wiring accessories is designed, developed, and managed in-house at the company's headquarters in Tamworth, Staffordshire, England, with production handled through long-term partner factories overseas."