Laptop wont turn on until i press power button for 5 seconds

Recently, I purchased a Dell Inspiron 3525 laptop. However, after a few days of usage, I noticed that when I left the laptop in sleep mode for a short period of time, it wouldn't turn on.  I tried turning it on by plugging it in, and the charging indicator light was on and the fans were on , but it still wouldn't turn on. To fix the issue, I pressed the power button for 5 seconds and then tried again, and it turned on. Interestingly, the date and time had been changed automatically after the issue occurred. This has happened 5 times now, and I have had to turn it on by long pressing the power button. However, every time it happens, the date and time automatically change. Should I be worried about this issue, and why is it happening