As Windows can not handle two folders with the same name, but RushFiles can, the PC client will rename the second folder by putting a timestamp at the end of the folder. That is the "weird" name.
The folder can be renamed in the PC client, under Shared folders. The names on the client can be renamed locally. Renaming it on the server afterwards will not change the local "renamed" name, as it will break links.
Imagine two Companies on your system that both share to the same person, and both use a share called "Projects". In this case, the user can rename it to "companyA Projects" and "companyB Projects", then all links on the PC will be set to these paths. Then if the Company renames it to something else, it will stay as "companyA Projects" on the local PC, so the links don't get broken. That is why the name stays.