Thanks for the report, and sorry about that!
This is a rare issue I still haven't nailed down the cause of. Sometimes it can be fixed by switching to a different level and switching back again, but if it continues to be an issue you can find a full save here which should will have everything unlocked for you - just paste it to your C:\Users\[User]\AppData\LocalLow\Devon Wiersma\Bombing 2_ A Graffiti Paradise (overwriting your Profile.bin) and you should be good to go! This will only affect your gear/tool progression and won't affect your paint data at all.
If you're able to send me the Profile.bin file you've been experiencing this issue with it will help me debug this for others be immensely helpful! :)