I wish I could advise you more but without knowing all the details it's hard @AgenceGrateau
You're pretty young to be using HRT so I'm assuming you've an early menopause or peri symptoms?
Are you using hrt for symptoms like flushes, moods etc or something else?
From what you've said, the HRT isn't creating a new HRT cycle and your own periods are still there at different time intervals.
A lot depends on if these irregular bleeds bother you . If you want HRT to control your cycles, you could consider the Mirena coil which usually stops all bleeding. Or, you could try increasing the Utrogestan to 300mgs. Or you could change to different products like a patch containing Norethisterone. This is a much more powerful progestogen and would probably stop the bleeding. But it's not body-identical.
It's not 'normal' (you asked!) because HRT usually creates its own cycle with a regular bleeding pattern. Your periods are doing what they would if you weren't on hrt- becoming irregular.
So you've either just go to accept that you're getting HRT to control your symptoms, but as you're very much in peri, you're going to have erratic bleeds or you change to a different progestogen or increase the Utrogestan.
If your GP is not supportive, ask to be referred to a menopause clinic, or if you can afford it, refer yourself to a private consultant.
As you're so young and have been using hrt since you were just over 40, you need a dr who knows what's what!