Help with leaking MDPE compression to water meter housing

[NCXo82ike]

Hi,

Please help me figure out what I'm missing. I have a plastic stop tap with water meter housing (no meter yet) at my boundary to the street. Anglian water fitted this in 2020 when the old metal stop tap failed.

 

I dug this (reasonably carefully) during other works in my garden and it was seeping at the connection to the meter. I have taken off the connector and refitted a new length of MDPE pipe. Since then it is leaking significantly.  I reconnected it as follows:

 

Nut (original)

Clamp (the split plastic ring, original)

Thrust ring (original)

O-ring (taken off a new 25mm straight coupler)

Meter housing

 

There was no pipe insert in the MDPE previously connected. I didn't see any o ring but I was working in poor light and may have dropped it. 

 

Any ideas what I'm missing? This is a DIY job but I've done a few similar things in the past. 

I can't easily find compression fittings to match- would they all be the same inside?

Hoping I can find a solution that doesn't involve getting Anglian Water to replace the whole unit.

[JohnMo]

See no mention of the pipe inserts, so did you have/install?

 

A video of assembly easier than loads if words 

https://youtu.be/QDJ2gUNuf-Q?si=lF9exiA8-baO2cDL

Edited November 16 by JohnMo

[NCXo82ike]

1 minute ago, JohnMo said:

See no mention of the pipe inserts, so did you have/install?

 

A video of assembly easier than loads if words 

https://youtu.be/QDJ2gUNuf-Q?si=lF9exiA8-baO2cDL

thanks JohnMo, I did actually watch exactly that video last night. 

I installed a pipe insert- there wasn't one originally.

 

I presume that was a problem with the original install? Surely having the insert in couldn't be the issue?