Market is influenced by subjetive perception of value. And it has been proved that once a sector is feminized, wages go down.

The fact is that with COVID, nurses weren't given a rise because they were guilt tripped. Also, there was many empty promises to improve their conditions that now are not being fulfilled.

By the way, glassdoor uses anonymous information. That means they don't have reliable information for an analysis. It is still useful, but won't help for the wage gap. Not just that, since people there are self reporting, you can have bias in the sample. Not intentional, but chances are that the people who use glassdoor only fit one specific worker profile.

Eurostat have better sources and data because the reporting comes directly from the companies and there is standard methodology on its collection.

But even in your studies, there is a wage gap that can't be explained away by "women preferring low paying jobs" or behaviour.