The GRID system is bugged in that way. If you want to salvage your game, you load it and left click as quickly as possible and turn off all funding for GRID.
Just enjoy it while it lasts because this will be fixed and will be more “risky” in the future.
Or if you just want to have infinite monies, don’t download the update.
Or save the file now so you can always roll back the mod if you don’t like the fix…
Also for future peoples who want to report this issue, DON’T!! Just look at the previous posts, it has been mentioned numerous times already and the modder knows this issue.