Silvia Lass-Adelmann

Check that the TM in your project settings for you new project is actually the one you think it is, and also make sure it's enabled.  Can you share a screenshot of your project settings showing the TM?

This is the TM it should be using - not DeepL, the DE-EN UK one. 

And this is the language pair the project is set to, so it should same language pair as the TM (seems to be a common mistake that people get the language pair wrong).

And this is an entry in the TM which Trados SHOULD have found but didn't. Also, it seems my TM is not being updated; I had eventually manually translated the whole document, then re-loaded it into Trados to check whether it would perhaps pre-translate after I had manually translated the whole thing and run both an "Update Main TM" and "Update Projekt TM" batch task, but no..... nothing.

Silvia Lass-Adelmann

Can you check the path to each of these TMs and make sure they really are the same?

Not sure I fully understand what you mean by that - I only have one TM that goes by that name, and all my TMs are stored in the same folder on the same drive. 

Silvia Lass-Adelmann

It won't be the first time someone thought that only to realise it wasn't the case.  So just thought it was worth checking.  If you hover over the TMs in each project you'll see the path.

Lol - nope, and it would certainly be something that could happen to me! No, but I don't  think it was that.

Silvia Lass-Adelmann

ok - so if you're sure you are using the same TM, and you're sure it's enabled, and you're sure your project settings are all correctly set to enable the match expected, then maybe we can take a look at this on Monday over Skype?

One more idea though... as I just realised you have 2017.  Try prioritising the TM over DeepL by moving it up and see if this helps?  Shouldn't make a difference but you never know.