We recommend trying to reboot your Wi-Fi -router which might help or play with 4G/5G (not 5ghz Wi-Fi) -mobile connection for smooth Stumble experience. Other reason might be RAM-management on your device. If you are switching between applications when the game going on this can cause disconnect too.
In reality, the RNGs used by online poker sites come as close to real randomness as possible, simulating random outcomes by running through millions of card combinations per second.