NHS, on probation, Covid symptoms absence- paid or taken from A/L?

[Miljea]

Genuinely asking for a friend!!

She was still in her probationary period at work as a HCP, she became symptomatic for Covid, so had to isolate. Her employer says that as she's probationary, she has to take that time as A/L rather than on full pay.

Does anyone know the rules, please?

That is absolutely incorrect. Your friend should contact her HR dept and let them know and request a copy of the relevant policy if they cannot access it themselves.