yeah i can see that now after further testing, im able to create them after some time passes
must have missed that update

Now there is a cooldown time to prevent the logo and name of a defunct company from being reused immediately.

I recall that this was added after a user reported a bug which was due to a defunct company's logo and name being reused immediately.

in 6.2.08(possibly before as well) when you merge your subsidiaries into your main company, they will kind of still stay in the game and add up to the global company limit, so at some point(after merging with a lot of your subsidiaries) you wont be able to create any new ones

you can recreate it with setting user script at 48 competitors at start - start game, create subsidiares under your main company and keep merging with them