Ok, so rather than just joining the throng and complaining about the "kk" update, here's a suggestion, somewhat based upon what others have said so far:
a.) Regardless of display format, eliminate the rounding. That is creating more confusion than I think was intended.
b.) if there is a legitimate display issue with the game that the large numbers are causing display issues, then just implement a single M if a numeric value is greater than 1 million, using a decimal point for thousands. Unlike the "G", the "kk", and other issues, I think it's fair to say that the "M" is universally (internationally) known and used. A simple google search can confirm this, I think.
For example:
529,425 = 529,425 (no change needed)
1,003,965 = 1.003M
3,854,945,623 = 3,854.945M
No rounding, just drop the hundreds.
Yes, this technically is only saving 2 character places/digits, but considering that the game was apparently handling billions just fine before this update, I think 2 digits is likely all that is needed to be addressed.
And I suppose I should note that this option is not one of the options listed on Discord.
Anyway, I hope this helps.
Edit: Here's a link explaining some of the issues with M, G, and K: