The OLED version of switch is a very cute game console, but the docking experience of this game console seems to have caused trouble for some users.
In the reddit section of the Nintendo Switch, there was reportedly a lengthy post. The poster of the post said that when his OLED version of switch is in docking mode in the base, although the TV will show that it is connected, there will be a continuous "about 4 to 5 seconds at a time" TV disconnection problem.
After some extensive testing, the culprit appears to be the "softer and more flexible HDMI 2.0 cable" included with the OLED version of the Switch model. While the Switch base is compatible with both HDMI 1.4 and 2.0, it appears that the 2.0 version of the cable will cause certain models of TVs to disconnect.
So, in short, if you have this random disconnection, switch to the HDMI 1.4 standard cable.