A video call works on the balcony, then starts breaking up when you move inside. The phone has not changed networks just because you crossed a doorway, but the signal reaching it can be affected by the building and by where you are within it. Before blaming the phone or switching settings, compare the connection in a few places.
Walls change the signal path
Concrete, metal surfaces, and several walls between you and the outdoor signal can make reception weaker indoors. This can be noticeable in an apartment, an office, or a house where the room you use is far from an outside wall. Try the same basic task near a window and in your usual work spot, keeping the phone and network setting unchanged.
Location is only one clue
If the connection is poor in one room but better elsewhere, the indoor signal path may be part of the issue. If it slows down across different locations, demand on the network or a temporary service problem could also be involved. One short test cannot identify the exact cause, but noting the time and location gives you a clearer pattern than relying on a single signal-bar reading.
Test before changing settings
Use the same website or task in two nearby spots, such as beside a window and at your desk, and avoid downloading a large file just to test. If you use the phone as a PC hotspot, place it where reception is better and keep it within a reasonable distance of the laptop. When the slow connection affects several devices or persists in different spots, check your provider’s service information before resetting equipment.