After looking into this, we can confirm that Proton Drive has been officially deprecated by rclone (classified as Tier 5 — no longer maintained or supported). You can see the current status here: Backend Support Tiers
Since RcloneView relies on rclone as its backend, Proton Drive support is unfortunately no longer viable. The fact that Proton Drive still appeared in the RcloneView remote list was our mistake — it should have been removed when rclone deprecated it.
We will release a hotfix shortly to remove Proton Drive from the remote list to avoid further confusion.
We apologize for the inconvenience and the time you spent troubleshooting this.