Why does the Redmi Buds 6 Lite experience lagging sound in some environments such as subway?

The strong interference environments such as train stations, subway stations and substations have an impact on the RF (Radio Frequency) performance of the Redmi Buds 6 Lite, causing the earbuds to lag when listening to music. Bluetooth products all have this problem, which is normal. When used in environments with low interference such as offices, coffee shops, and homes, there will be no lag problem.
Note:
The effective connection distance between earbuds and mobile phones in an unobstructed environment is about 10 meters. There will be a sound delay or Bluetooth disconnection beyond the effective connection distance.