Way slow loading home movies on Apple TV with Home Sharing

Playing home videos on Apple TV is convenient but painfully slow. Doesn’t matter if I’m connected by Ethernet or WiFi. Example: a 2:27 min video doesn’t start to play for almost 2 mins (1:53). The time strip at the bottom of the video fills to about the 1 minute mark. I also have a Plex server on my Apple M1 Mini and the Plex app on Apple TV. With Plex the same video starts playing in 3.8 secs. I have no streaming lags with Netflix, YouTube TV etc. — only from the Home Sharing computer on Apple TV.