I have encountered this problem many times with Trados. I solved it by using OmegaT, a free CAT tool.

It has no problem with large TBs. You have to convert the TB to Excel file by using Glossary Converter and then by using Notepad to a txt file,

You have to create a project in OmegaT. In the source files folder of the project you copy the Trados bilingual files.

You copy the notepad termbase file to the glossary folder of the project in OmegaT project folder.

Then you can work on the files and the term recognition works fine in the glossary window of OmegaT.

So said to read this, Paraskevas. And unfortunately I think you are right. After one month of not getting any help here, I was also trying to have some support via chat. 

After two weeks of intense interchange of messages, screen shots, databases etc, the support told me that MAYBE they think this is not a bug or a problem, but what they called "intended design", i.e. The way the program was really designed and the intention is for it to work like this.

In face of this answer I had to continue using MemoQ. 

And to finish it with a cherry on the top, when then I told the support that the program lacks a very basic feature and is useless in my point of view despite being very expansive, and therefore I'd like to have a refund, they told me it was not possible because a month has passed (of course, losing time with the support that instead of saying upfront that this was not a bug, kept me asking to do a lot of things and tasks).

Best Regards 

Yair Alon 

Apologies for not getting back to you.  A top for the future is to tag the person you reply to so they get a notification.  In the same way you do with pretty much any social software just type the @ symbol and then select my name.

I don't know what support told you or what you told them but can you share a short document that doesn't work for you along with a termbase?

Yair Alon 

Apologies for not getting back to you.  A top for the future is to tag the person you reply to so they get a notification.  In the same way you do with pretty much any social software just type the @ symbol and then select my name.

I don't know what support told you or what you told them but can you share a short document that doesn't work for you along with a termbase?

Sure I can Paul. How do I share that with you?

Yair Alon 

Great... you can send this to pfilkin at sdl dotcom. Might be best to put it onto a shared drive if it's large and just send a link to make sure it doesn't get bounced.

Hello, Paul . Thanks! Just sent you a package of the project. See if it has all you need please.

Yair Alon 

Thank you... was just missing the termbase ;-)