Multiway Registration quality issues

[Chernobrovkin-AD]

I performed multiway registration with code from docs:
https://www.open3d.org/docs/release/tutorial/pipelines/multiway_registration.html
I just substituted input with my 8 clouds:
https://drive.google.com/file/d/1ewB_hHmazMysaT0dklnekcz9RbjgDUWj/view?usp=sharing
Result cloud:
https://drive.google.com/file/d/1BstsxOBF0xpd8O9kRdtJ0yrf4KDlhz7_/view?usp=sharing
Screenshot before:

Screenshot after:

Final result look worse than input. Is it algorithm issue, or something should be tuned? Or something bad with the input?