Bleeding or spotting is common during the first 6 months of HRT.
After that, it needs to be investigated if you have have gone without a period for 12+ months prior to starting HRT.
Utrogestan is licensed for oral use only.
However, many ladies take it vaginally to avoid unwanted side effects.
It might be that the utrogestan isn’t sufficient to protect your womb lining, hence the bleeds.
In theory, vaginal use should be better because as you say, it hits the right spot.
After 6 months, if you are still bleeding, you may want to think about switching progesterone? The coil is one option, but there are others.
Good luck .