This is probably Android TV polling Jellyfin for new content for the Android TV home screen. IIRC, Android TV does this check every 5 mins, which lines up with your activity log.
Jellyfin 10.10.7 (Docker)
Ubuntu 24.04.2 LTS w/HWE
Intel i3 12100
Intel Arc A380
OS drive - SK Hynix P41 1TB
Storage
4x WD Red Pro 6TB CMR in RAIDZ1