I have no idea regarding Raspi - my Nextcloud with MariaDB behind Traefik running as Docker on x86 Intel Celeron based Qnap-453 NAS reaches 200+ Mbit/s when moving big files around (movies, .iso files etc.) with the client, when the client is on Wi-Fi. Browser up-/download in fact seems to be limited at 100-150 MBit/s = 10-20MB/s… Maybe the limit is related to Wi-Fi (unfortunately all my LAN ports are used now…) Interesting fact I have to investigate deeper.
the screenshot shows parallel upload and download of >500MB file to my local NC instance over Wi-Fi. It looks the connection in limited somewhere - but at least the system is capable to handle more than 100MBit/s in both directions. I will run wired tests as well - maybe some limit exists in Traefik.
It’s not enough to judge about your setup - maybe you measure different things? like enforced https for Traefik connection and plain http for direct NC connection? is there a difference in upload vs. download? Can you share bandwidth measures from internal LAN as well?