How long are you leaving the male in for? To me it looks like you are opening the bin and photographing as the male is attempting to line up. You may be distracting them too much. Try just once leaving the male in for 3 days without disturbance. Meaning do not go into the room, past the tubs, and certainly not open the tub. Check the tub on day 4. If they are lined up but not locked, check back 12 hours later. If they are separate then remove the male. Pop him after to see if he has bred/ Has the female paired before? They may need one long pairing to get them started. I had one pair this season lock at 48 hours and stay locked past 72 hours. I was finally able to remove the male on day 5 after they were clearly separated. Sometimes you have to bend the rules and go by what the animals are doing instead of the textbook standard.