High-precision coordinates issue with boost::voronoi

Question

While experimenting with voronoi_advanced_tutorial.cpp higher-precision coordinates I've noticed that one of my output diagrams exhibits a math error (apparently). The diagram does not exhibit such errors, however, with the default coordinates (int input and double output).

Default int and double coordinate system.

The following figure shows the output diagram primary edges (orange) for a set of input edges (black). Everything looks fine.

High-precision coordinate system.

Once I change to boost::int64_t input and long double output the diagram exhibits some errors. From what I could find out, it is related to the internal-right rectangular shape. Only the internal-left and the outer rectangle works. Once I insert the right one, however, it fails.

I can't figure what is causing the issue and the int_type to ftp_type conversion seems correct. I've also shifted the polygon shapes far from coordinates with 0 - i.e. (0,0) -> (100,100) - but the problem persisted (it was visually "better" at least). Any suggestions on what to look for with this issue?

You can find the Full Code available through Wandbox. I've tried GCC 11.1.0, 10.2.0, and 9.3.0 with boost 1.75.0 and 1.77.0.

EDIT: On the high-precision coordinate system figures the 4th is a zoom from the 1st configuration (i.e. the outer rectangle and two inner rectangles). I've used the purple arrow to try indicating such "zoom". In practice I've removed those points that exploded, thus rendering unreadable the 1st figure.