Lovebird issues

[Thor1]

i have had a pair of love birds for about 4 months and they have made a lovely nest with the palm leaves i have given them and i check their nest every now and then and today i checked again and no eggs. no problem there however as i got rid of some of the grass that was growing in the cage i found four eggs. not in a pile together but all apart from each other and on the other side of the cag from the nest box.
my question is why? and is there something i should or dhouldnt be doing to improve their breeding chances.