In the end, this comes down to the problem that I can't re-add an already encrypted folder. To reproduce, add a folder with an encrypted key on Device A, and add the read-only encrypted key without the decryption key on Device B. Let some files sync. Remove the key and the folder (not the contents) from Device B, and then add the same folder with the same key again. The newly added instance now has a third key, irrelevant to the original.
When adding an encrypted key (i.e. a read-only key with no decryption key) to an already existing folder (that was synced earlier with the same key), the folder is added with an entirely different, unrelated key than the one provided, and it indicates no peers active. I've gone ahead and confirmed that it actually does use the new key (by adding the new key on another device) and it starts syncing the encrypted files. How can I add an already existing encrypted folder and start syncing the files with other nodes using the initial key? Thanks. P.S. I tried adding debug logging,