Boot Loop

Hi, i have a question regarding my iphone se (First Gen). Two days ago my lock button is not working then i used my assistive touch so that i can still hard reset my phone, unfortunately when i hard reset it, it stays on the logo (on off with the apple logo) i researched it and they call it boot loop. But when i plug it with my charger it opens. My question is, why is that happening? Is it safe? I mean it may crash my phone or what? By the way my ios version is 13.5. Please help. Thank you.