The launcher server browser is great for quickly joining a server and automatically downloading all the mods. However, when the mod list gets up to about 20 mods, the launcher just gives up.
This is what it looks like: https://i.imgur.com/XWFLJ4h.png
If a couple of mods are removed (doesn't matter which ones), it will detect the signatures again.
Related forum thread: https://forums.bistudio.com/forums/topic/203122-how-to-get-required-addons-to-show-up-in-launcher/
According to people on the forum and Discord, it has to do with the maximum amount of data that the protocol can send to the client.
@BISWizard ,might help here...
With more than ~ 26 .bikey files in the keys folder the server alos does not show up in the launcher at all. connecting from the ingame browser works, although it won't show the modlist aswell.