No issue since there is an insurable interest, correct me if I'm wrong though, not that well versed with General Insurance.

Take very good care of your mum then cos she may choose to give the house to someone else...

But seriously if you are the one paying for it then ofc the insurance must be on your life (and nominate to your mum or absolute assignment to the bank) and not your mum.

If God happens to love you more, then the insurance will be paid to either your mum or the bank to settle the loan.

Normally if it's fire insurance, it should be under the houseowner name, but in this case, you will have to clarify with the insurance company you bought with, or read within the policy guideline on insurable interest.

Because it doesn't make sense that you don't own the house yet you buy the fire insurance for it which belongs to your mom.

Same example would be

A landlord rent out his unit to a tenant but the tenant buy the fire insurance for the property instead. But in this case it is  make sense because there is no insurable interest as the tenant don't owe the bank any money nor do they own the property itself. It is the landlord responsibility to insure it under his/her name.