Multiple users with one IP address

I am using a Pickaxe tool within a training workshop for an organisation (where everyone has the same IP address). The Pickaxe tool didn’t work for them, even though it was still working if a user accessed it via a mobile phone, or a different IP address.

Is multiple people using a Pickaxe tool at one time from one IP address not permitted? And if this is the case, can you suggest a workaround?