Switching pharmacies while on Wegovy - new place won’t accept me because BMI is now <26. Normal?

I’m on Wegovy 2.4 mg, started earlier this year with a BMI just over 27, and I’m now just under 25 thanks to the treatment.

I tried to switch to a cheaper pharmacy, but the new one (Family Chemist) said they won’t accept new patients with a BMI under 26, even if you’re already established on treatment.

This seems bizarre as it could have the effect of tying you forever to a specific pharmacy if your treatment is successful. Has anyone else run into this? Is this a common pharmacy policy or just specific to them?