I have a laptop A running Windows 10, and a phone B running android.
I have ethernet connected to A, which runs properly with high speeds.
I turn on hotspot on A and turn on wifi on B, and connect. More often than not, I won't be able to browse internet on B in this configuration. This is while internet on A runs smoothly; and mobile data or any other wifi connection on B runs smoothly.
Note that this is quite random: sometimes the A-B connection runs nicely; but the case that it won't is more often.
How to troubleshoot this, and what are the possible causes?