IMAP subscription for new nested folder ignores hierarchy?

Description

After creating a new folder “buffer/unsub” in Mailspring, it apparently registered an IMAP subscription for folder “unsub” (ie. excluding the folder hierarchy).
This was totally harmless from Mailspring’s perspective – I didn’t notice until months later when I switched to Thunderbird and found (a) my “buffer/unsub” folder was absent but (b) I had an empty top-level folder called “unsub”
I’m 95% sure I created this folder in Mailspring, there’s a small chance I created it on my phone (FairEmail)

To Reproduce…

Steps to reproduce the behavior:

Expected Behavior

Screenshots

Setup

  • OS and Version: Windows 11
    • Installation Method: MailspringSetup-1.17.1.exe
  • Mailspring Version: no clue what version I was on when creating the folder

Additional Context