Cannot disable shallow fetch on shared Git repo

Configuration :

• a shared Git repo, initially configured with shallow fetching option activated
• the repo is accessed through ssh, submodules support is enabled
• multiple plan using this repo, each having multiple branches

Steps to reproduce :

• disable shallow fetching option on the shared repo
• run a branch on a plan that uses the modified repo

Result :
The run logs still show "Will try to do a shallow fetch".
The only way we could find to force a full fetch was to declare a plan-specific repo with the option disabled.

Update : the shallow fetch seems to also happen with the non-shared repository with the option disabled. So I cannot find a way to disable that shallow fetch functionality.