Solved

Unable to boost league

What did you try to do?
Tried to donate a boost to a league I don't race in, which, per Jack's main forum post about new league systems should be possible. It says you don't have to be a member of a league to boost it.

What happened instead?
Simply doesn't work.

Did the problem happen while using wi-fi, mobile data, or both?
Wi-fi

Did the bug happen in the app, on PC, or both?
PC

What operating system is your PC?
Windows

Which browser did you experience the problem in?
Chrome

Can the bug be reproduced?
Yes

Additional comments:

Tried again and it worked. Thank you!

I can confirm that it works for me!