If you face lag issue on one ui 4 beta 2

[SVivek]

You can do hard reset.. it will solve the lag issue... handset will start working fluidly. 

[RohanVIP]

Still getting lag after hard reset

[IndiaBetaTeam]

Dear Samsung Member,

Greetings from India Beta Team!

Thank you for sharing your feedback. We appreciate the time and effort you have spent to share your valuable comments. 

Thank you for writing to Samsung.

Warm Regards,
India Beta Team

[Oms004]

Try below workaround. It will definitely work.

First, turn off always-on display.... 

Second, turn off show charging information under display option..... 

Third, turn off fingerprint always on under fingerprint settings.....