Hi @lowhic74, there are numerous discussions here that talk about synology and tv issues. I don't know which of these if any address your particular issue but you might want to look through them.

@lowhic74 said:
Tv Show never been find automatically
Hello,
I hope you can help me...
I've been searching for a solution for a long time by myself and with Google, but I don't find a solution working for me.
I'n using a synology with "videao station" My API Key is working fine with movies, but not with TV shows.
I have to manually search TV show information most of the time.
There are in their own folder as mandatory. I tried to reindex, but same result. I have screenshots if needed.
Do you have any idea please ? Thanks a lot for your time.
Best regards Loïc

Some time ago I made a list of conversations that had some solutions for Synology.
It might make your search easier.

Some Synology NAS/DS Video users have appeared reporting problems.
There are different versions of Hardware and different versions of Software.
And the problems are not exactly the same for all these versions.
One of them said there was an update from Synology.
We don't know yet but it looks like this update came with this issue.
So I suggest getting help from Synology's website.
https://kb.synology.com/en-my/DSM/help/DSM/SupportCenter/SupportCenter_desc?version=6

See if any of these threads can help solve your problem.

Synology NAS/DS Video Reports

2023-05-15 https://www.themoviedb.org/talk/634c0d22a61de1007effbb93

2022.08.07 : My issue is now resolved with Synology support.
https://www.themoviedb.org/talk/62315048befd910074c5db4c#62ee3bd29369a2007dc2252b

2022-04-10 https://www.themoviedb.org/talk/62535423ca4f67095e92f4fd
https://community.synology.com/enu/forum/1/post/149352
2022-03-15 https://www.themoviedb.org/talk/62315048befd910074c5db4c

2021-11-09 https://www.themoviedb.org/talk/618ada421cfe3a002a4f89d1
2021-07-21 https://www.themoviedb.org/talk/60f89a1b07e281007d7f3ffe
2021-04-10 https://www.themoviedb.org/talk/60716402dfaae9002b30b85c
2021-02-23 https://www.themoviedb.org/talk/6035201c0d294400405ab8a0
2021-02-17 https://www.themoviedb.org/talk/602ca712db4ed600406bb052
2020-09-01 https://www.themoviedb.org/talk/5f4f012b47c9fb0037742b1c

On the topic
https://www.themoviedb.org/talk/60f89a1b07e281007d7f3ffe#60fd75a9c439c00029f370d5
https://www.themoviedb.org/talk/60716402dfaae9002b30b85c#613c26ecdbf1440062fd16c3
the user got some responses from Synology.

Travis Bell reported the ports used by the servers

Hi @USER, there's only 2 ports that can be used to communicate with TMDB's service.
These are your standard HTTP 80 and HTTPS 443 ports.

If your problem is not similar to any of the above cases, I suggest contacting Synology Support.
https://kb.synology.com/en-my/DSM/help/DSM/SupportCenter/SupportCenter_desc?version=6

Thanks both for your answer. I going to look at the link this we ;)