Disclaimer not a lawyer, just remembering stuff from helping M with her exams:
Most (?) crimes have two elements, the act/effect and the intent. Both parts need to be present in order for the crime, as legislated, to have taken place. Sometimes the intent part can be covered by recklessness or negligence but the law in this case it’s clear that there needs to be intent to cause alarm or distress. Oddly though it looks like it isn’t necessary that the genitals are actually seen by intended person.
As @aboynamedgoo pointed out the law commission is looking at it but I think if the new offence of cyber flashing retains the intent to cause alarm or distress requirement then it won’t fix anything. It would straightforward to claim you were intending to arouse or flatter.
The law is weird and inconsistent and stuff like this underlines how “out of touch” it can be. And as M would often point out to me, it may seem logical that if one law functions a certain way then another one would do too, but it isn’t and it doesn’t.
Sorry you’ve had to deal with seven years of harassment, grim