Network operators and electricity sales are decoupled EU-wide, meaning that the network operator doesn't really care if you feed in energy because they're not selling you any anyway. They're just operating the network, getting paid by whoever uses it. They care about the stability of the network but those solar inverters stabilise the frequency it so it's actually a net positive for them.

Of course, your municipality might have sold off its utility and now you're dealing with private sharks who invest nothing and just bleed everything dry. Or you're dealing with a CDU council and major who hate renewables because it's what the greens want.