Phone restarts after entering Pin Password

my oppo reno 2 phone restarts after i input the pin password, last night i think i forgot to charge my phone and let it run all night and of course the battery drained.

I charge it till 65% before opening it, then after a few minutes i input the pin password then my phone just freeze, still the power button function when i press it, it just locks then if i press it again, it won't open. Phone restarts after that.

anyone experience this? can you help me?

thanks!!