Moving your phone slightly farther away from the Wi-Fi router can sometimes improve the connection quality, even though the phone is farther from the signal source.

Explanation: Wireless connection quality is not determined only by distance or signal strength. Radio signals can be affected by reflections, interference, and multipath propagation. Changing the device position can sometimes improve the quality of the received signal, even if the device becomes slightly farther from the router.

Source: Cisco - Multipath and Diversity https://www.cisco.com/c/en/us/support/docs/wireless-mobility/wireless-lan-wlan/27147-multipath.html

A phone showing fewer signal bars can sometimes provide a clearer voice call than a phone showing full signal bars.

Explanation: Signal bars mainly represent signal strength, but signal strength alone does not determine communication quality. Mobile networks also consider factors such as interference and noise. A device with a stronger signal can still experience poor quality if interference is high, while a device with a weaker signal in a cleaner radio environment may provide better communication quality.

Source: 3GPP Explorer - Reference Signal Receiving Quality (RSRQ) https://3gpp-explorer.com/glossary/rsrq

If an internet speed test shows a high download speed, this means your online gaming and video calls will be excellent, assuming hardware is not the limiting factor.

What makes it false: Real-time applications such as online gaming and video calls depend not only on download speed, but also on other network characteristics such as latency, jitter, and packet loss. A high download speed alone cannot guarantee a good real-time experience.

Source: IETF RFC 3550 - RTP: A Transport Protocol for Real-Time Applications
https://www.rfc-editor.org/rfc/rfc3550