Deleting any data fails in docker Specify 7

I’m running just-specify7 docker container and logged in as collection admin (unaltered default role). Any data deletion attempt fails with this kind of message:

Forbidden
You don’t have permission to access /api/specify/preptype/4/ on this server.

or

Forbidden
You don’t have permission to access /api/specify/spquery/2/ on this server.

or

Forbidden
You don’t have permission to access /api/specify/agent/12522/ on this server.

Interestingly the same kind of DELETE requests executed through the API (https://specify.herbier-guyane.fr/documentation/api/tables/) do work without problem.

Any hint please?

Just like the 413 Request Entity Too Large error it is our reverse-proxy that somehow block the DELETE api request.

Solution must be sought with our Network IT staff, and is not linked to Specify 7 docker composition.