CC @ivankravets
The Python cryptography change to use Rust seems to have caused major headaches (HowTo: Raspberry Pi 3 as remote agent (Oct. 2020) - #13 by danielsvane) but was supposedly fixed by pinning the version (Use Rust-less "cryptography" dependency for PIO Remote · platformio/platformio-core@dbc73f5 · GitHub). Are you 100% sure you’re running with the latest PlatformIO core? (pio upgrade --dev)