I'd recommend a diagnostic check to see if any fault codes flag up.
Could be an issue with the heater matrix or with the heaters temp sensor etc.
Also is the engine temperature normal (90 degrees). If not could the thermostat be failing?
I'd recommend a diagnostic check to see if any fault codes flag up.
Also how old is the cars battery? I ask as a failing battery can cause cars to have various unusual electrical issues.
By the way you're English is fine 🙂