Deviantart: folder "does not exist"

[urodoc]

When a deviantart.com gallery has a subfolder, occasionally gallery-dl fails saying "The folder does not exist", even though viewing that folder in the browser works fine, and shows the exact same address. Also tried with explicit -u and -p acct info, no difference. Example:
C:\gallery-dl>gallery-dl -v https://www.deviantart.com/dr-benway/gallery/91784/arty-shots [gallery-dl][debug] Version 1.8.7 [gallery-dl][debug] Python 3.7.3 - Windows-10-10.0.17763 [gallery-dl][debug] requests 2.22.0 - urllib3 1.24.3 [gallery-dl][debug] Starting DownloadJob for 'https://www.deviantart.com/dr-benway/gallery/91784/arty-shots' [gallery-dl][debug] updating default urllib3 ciphers [deviantart][debug] Using DeviantartFolderExtractor for 'https://www.deviantart.com/dr-benway/gallery/91784/arty-shots' [urllib3.connectionpool][debug] Starting new HTTPS connection (1): www.deviantart.com:443 [urllib3.connectionpool][debug] https://www.deviantart.com:443 "GET /api/v1/oauth2/user/profile/dr-benway HTTP/1.1" 200 1786 [urllib3.connectionpool][debug] https://www.deviantart.com:443 "GET /api/v1/oauth2/gallery/folders?username=dr-benway&offset=0&limit=50&mature_content=true HTTP/1.1" 200 1002 [deviantart][error] The folder at 'https://www.deviantart.com/dr-benway/gallery/91784/arty-shots' does not exist