I can't start connection with fiber optic internet after instalation of wall socket in my house.

Yesterday they have installed wall socket in my home to be able to connect to fiber optic internet. Activation day was 2 May. Today is 3 and I have tried everything as I suppose. I just don’t understand why when I check status of my order where I can find “Start met aansluiten” button, I can’t press that button as it’s grey. I already called customer service twice and they’ll be in touch in 3 days. I don’t want to wait 3 days as I was already waiting for that instalation since November 2022. Is there anything else I can do from my side at this moment or just wait? Light “connection” on the wall socket and “internet” on Kpn box 12 modem are flashing which mean as I suppose that there is just no stable connection?

As my previous DSL internet was connected, LED “Internet” was stable green light instead of flashing.