Christine, if you are bleeding randomly then you shouldn't be on continuous HRT. So that's the first easy thing to change.
You can either do sequential or you can do continuous but take a 5 day break to schedule a bleed. The latter is probably a better idea in late peri, because you will get all the benefits of continuous but also scheduled bleeds.
How to go about this? The next time you start to bleed, stop taking your utrogestan for 5 days and allow the bleed to happen. Then re-start it again. See how often this happens. You will likely find a pattern to it, meaning that you are still bleeding every X days if you allow your cycle to happen. Usually cycles get shorter and closer together at first (mine are now every 23 days) and then longer and further apart before they stop totally.
It sounds to me like you have been put on continuous too soon and your own cycle is still happening.
Secondly, if you are on a 75 patch, 100 utrogestan continuously is on the low side. It would make better sense to take 200mg continuously (with that 5 day break). If you get progesterone side effects at that dosage, try 100 orally and the other 100 vaginally to avoid absorbing too much systemically.
If even that doesn't work for you, you might want to consider a Mirena coil which will completely stop all bleeding so you can forget about all this and you can even increase estrogen further if needed without worrying about it - it will protect even then. You don't want to stop HRT for so many reasons... But there are loads of options.
If the Mirena coil isn't an option, there are synthetic progestins which have a better effect on stopping bleeding than utrogestan does. You could add in desogestrel POP for eg, which is used as a contraceptive alongside HRT if women want to prevent pregnancy. It's fully approved and kosher to use it as well as utrogestan and it will stop the bleeding. (Sometimes there is some brown sludge for a while but then it will all stop.) Basically there are loads of options...
Have a read of this link for all the licensed options and tell your GP what you want to try (don't ask):
https://thebms.org.uk/wp-content/uploads/2021/10/14-BMS-TfC-Progestogens-and-endometrial-protection-01H.pdf