No details here to go on. Can't tell much with one side of one comb. There are several reasons you don't find eggs. You didn't look far enough. Queen quit or died. Swarm happened.
How often do you inspect?
You also have some comb fins being built perpendicular to the frame there. The frames need to be pushed tight together to prevent that. Or, it's plastic foundation without enough wax on it and they don't like it.
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