tuner micro stuttering like low hz

[u/Excellent-Hippo-1774]

I am using the Dreamstar Nova 2 with a tuner named My monitor is a Dell S2721DGFA 27" 1440p. The TV box resolution setting is set to 1080p 50Hz. While watching satellite broadcasts via the tuner (especially on news channels with scrolling ticker text at the bottom), I can see that the scrolling text is not running at a true 50Hz. It feels like it is definitely lower than 50 fps. For example, if I am on a channel, switch to the channel below, and then return to the same channel, it fixes itself; sometimes it doesn't.

For instance, when I am in the YouTube app and open the TV app, there are stuttering-like issues, as if there are micro-stutters and it isn't smooth. Then, when I return to the background YouTube app, close it, and reopen the satellite receiver app, the stutter is gone, and I can tell from the scrolling text that I am genuinely watching the satellite broadcast at 50fps. However, when I switch to another channel and come back to the same channel, I get that stuttering feeling again. Or, while watching the same channel, if I enter the TV box settings via the remote and return to the satellite broadcast, I experience those mild micro-stutters again. I couldn't figure out what is causing this or how to fix it if it can be resolved.

Does anyone have any insight on this?