Eigen 3.4.1 and 5.0.0 are available since 2025-09-10.

There are some breaking changes in 5.0.0 and many bugfixes, which often backported in 3.4.1.
https://gitlab.com/libeigen/eigen/-/releases/5.0.0

So here are the expert of your code to check for changes or new possilities.

So perhaps 5.0.0 is not compatible and this is also an information.