Sounds like yours should spawn soon but might not hurt to remove pleco and the other 3. Ours just spawned 2 weeks ago and they were alone at the time. They also seem to like lots of sand also check maybe yourrs are holding already.
If they are holding you should be able to see a swelling in their throat. This maay be visible I am not sure as my wife noticed ours holding.but ours ever held the eggs only the fry.
I read though that they will hold the eggs as well which would look like they were eating them. Have you ever seen peacocks holding their eggs your Geo's should look similar. Both parents will hold so don't worry.
I think that is right don't want to eat their fry. Do you have some sand on the bottom as I think they like it Ours were about 3 yrs old when they spawned and we are not really sure what triggered it. Kinda think it was when I warmed the tank up as it had been quite cool. As for food we were feeding North Fin pellets Cichlid formula and 4mm large fish.
I have read that they will hold the eggs not just the fry so be careful. Our male got rough with the female and we separated them. Then my wife pulled the fry as soon as they were free swimming. Glad to hear your luck is changing.