Unable to write file error when using object storage (digitaloceanspace)

i’ve switch my storage from local to Digitaloceanspace. im after settings with the correct key, URL, secret the test connection works well.

after moved all my existing files and folders from my server folder /var/opt/mattermost/data to digitaloceanpspace folder, im also able to see all the files appears in the chat room as well.

the problem here is when i try to upload files, error appears,

{"level":"error","ts":1627824142.7939558,"caller":"mlog/log.go:251","msg":"Unable to write the file.","path":"/api/v4/files","request_id":"6wmg6e4qgjyajqng3bdhkz9gjr","ip_addr":"","user_id":"tzrj9o9wftg388bxztcgnfexyw","method":"POST","err_where":"WriteFile","http_code":500,"err_details":"unable write the data in the file mattermost/20210801/teams/noteam/channels/kdajrixo17bwfjs4z8zhfg8r5c/users/tzrj9o9wftg388bxztcgnfexyw/zrecuft64bg83mezn16a7m7wia/2021-08-01 00-01-22.csv: The specified key does not exist."}

im pretty sure the permission to write in digitalocean is allowed.

anyone has successfully setup DO space in their self hosted version before?