Hydrolayer hides lakes in some regions on Topo maps

There appears to be a problem with the Hydrolayer on the standard Topo maps in some regions.

In Italy, lakes are not displayed at all when the Hydrolayer is enabled. In Spain, lakes are displayed significantly smaller than they should be. There may also be issues in other regions that I have not checked yet.

In Germany, the lakes appear to be displayed normally.

Interestingly, this does not seem to be a problem with the Topo Pro maps, where the lakes are displayed correctly.

This can be reproduced by switching the Hydrolayer on and off: the lakes appear/disappear or change size accordingly.

Could this be a problem with the Hydrolayer data or its rendering on the standard Topo maps?