As a qualified EFL teacher, I once attended an introductory session about helping female immigrants with their English.
I was keen to do it, until I realised that it was virtually all to be done one to one, in their own homes, because all too often they were not allowed (by husbands or other male relatives) to attend classes. Presumably because there might be men present.
I declined, largely because I infinitely prefer teaching a class, though I have since helped an Eritrean woman, one to one in her own home, long term. She’d have happily attended classes, but still had a toddler at home, her dh was working full time, and there was no available free childcare - she could not have afforded to pay.
A Swedish friend’s son married a Chinese-Malaysian woman, and they later moved from KL to Sweden. Until she had reached a satisfactory standard in Swedish, his wife was not granted citizenship.
IMO we should do the same here, and refusing to attend classes because of ‘cultural’ aka religious issues, should not be a valid excuse.