My recollection is that by default, OBS Studio does NOT break up the videos.
However, there is an option for the user (you) to change that.
Also, when you write OBS Studio 'transfers', that word is unclear.
Typically a user either 'Streams' video content (which could break up into pieces *if* network disconnect and settings at CDN (twitch in this case)
Or
A user Records locally, and later 'Uploads'.. and typically the user does this manually (vs using OBS Studio)
So are you referring to streaming, and that is getting broken up? if yes, see pinned post in this forum on posting OBS Studio log. And I'd recommend running log through Analyzer first. (links to both in my .sig). This could easily NOT be why, but I suspect you are disconnecting (for whatever reason) and that is the reason for the broken up videos. If you are reconnecting relatively quickly, then I'd further suspect a Twitch setting that needs adjusting to NOT break up the videos.
Solving for network disconnects, if that is your actual root cause problem, would be advisable