Dropbox.com not accessible via desktop, throwing weird error

Hello, I am receiving error: NET::ERR_CERT_AUTHORITY_INVALID
Here's what I can tell you: I am an expat living in Indonesia. I know there are some govt blocks but Dropbox is not one of them and I can still access it on my phone no problem, just not my PC. I can use a VPN and get past govt blocks, but still not able to access dropbox.

What I've tried so far:
- Tried using a VPN (and not)
- Updating my date and time
- Turning off my firewall and antivirus
- updating my OS and browser
- Cleared HSTS in Chrome settings
- Cleared cache and everything else relevant since "all time"
- Tried using a different browser (Edge, Opera and Chrome)
- Tried connecting to my mobile hotspot instead of my home wifi

System: Windows 10 Home, 64-bit OS, HP Omen

I believe that's about it. If you can help me, as I said, I am truly desperate.

I posted this on the windows help forum, and after no success they suggested I post this here. I really have no clue what to do.

Thank you!