If you update squads when starting a career you only have space for 7 subs on the bench instead of 9 which it should be, this needs updating without having to start career all over again
Ideas
Yes there is a bug when not using default squads.
When I spoke to support they said the team are aware and are aiming to push a fix sometime next month. Suggested workaround at the moment is to use default squads and update transfers manually.