I mean majority of the countries China is going through (for BRI) are probably worse than Montenegro in some of the issues you mentionedAll of eastern Europe is like that. Corruption, zero planning and a complete lack of capital resources. All development they've had since 1989 is because of the EU gravy train, before that it was the Soviet Union. They now have low birth rates and a significant proportion of their youth have migrated to western Europe. Eastern Europe is fucked.
Once the EU gets fed up funding their largess they'll go back to pre-WW2 third world standards. Unless they can find a new "daddy".
This is what you have to deal (on a more and more regular basis) with as the project progresses blaming the governments, getting angry/annoyed is counter productive
As there's a reason why loans/investment doesn't go to these countries
Precisely because of the reasons you mentioned but China took that risk now you'll have to face the issues
By A- renegotiating, scandals B- taking over assets
All of the things west warned about when it comes to these projects
You can't shift all the blame on bowrrowers, lenders also have responsibilities when it comes to loans (like when you give loans to sub prime buyers you can't get away by blaming the borrower and shifting all the responsibility to em without you suffering from the consequences)