RiseupVPN for Linux: problems with autostart

I installed RiseupVPN for Linux via snap as explained by https://riseup.net/en/vpn/linux.

In most cases, the application automatically starts, VPN turns on and the green systray-icon appears.

Two irregularity occurred so far:

1. On bootup, no systray-icon appeared and no vpn connection was established - but when checking the active processes, RiseupVPN ran. Killing and restarting RiseupVPN eliminated the problem.
2. On bootup, the systray-icon appeared, but stayed gray. When checking the internet connectivity, a connectivity delay appeared initially. Meanwhile, vpn connected - as if it was triggered by me testing the internet connection.

System specification:

• OS: Ubuntu 18.04.1 LTS
• Kernel: 4.15.0-42-generic
• RiseupVPN: 0.18.11