Freuqent waking at night(long post ahead)

I have a 32 months old boy. He doesn't need to night feed, only drink fm before bedtime. However, he doesn't sleep smoothly all the way. 2 to 3 hours after he sleep he will start to make noise or cry..back to sleep and then wee hours wake up cry 2 or 3 times.. on a good night, sometimes he can sleep all the way without making noise. Usually he wakes up to find his pacifier that has dropped off from his mouth, or just want to pat etc. Every once in awhile, he will have unconsoleable crying in the night. Pacifier checked, pat, no urine leaking etc. Last night he woke up at 12am crying and is unconsoleable. My husband was just starting to feel unwell down with bad sore throat and also tired from working so he just wants to have a good rest. However my toddler kept crying and we couldn't console him in the end husband slapped him twice in the face. Later on, he still make a few noises throughout and one of the time I patted his chest and held his hand and he fell bk asleep right away. However this morning at 7am he wakes up crying uncontrollably again and husband got mad drag and beat his hand and legs and carry him inside the storeroom and close the door. Less than 1 minute I went to open the storeroom door and try to calm him down. Was in the kitchen to fill his water bottle and give him water he broke down again lie down on the kitchen floor crying and shouting. I just let him shout and say u cry finish already stand up. It works. My heart broke several times last night. My boy is still not able to speak well yet (jus started to speak at 2.5yo when he sees dolphin on YouTube etc but not very clear pronunciation, some words are clear like ok, orange etc.) Last night I had no idea what happened to him and as he still can't tell us what he want yet and daddy is sick tired and frustrated. I drag to know what will happen tonight again. BTW I just had a newborn 2 weeks ago. My boy was coping well with his little sister and sayang her too. Not sure if it's the presence of newborn? However little sister is currently sleeping in a separate room with nanny. After nanny left, husband offered to take care of newborn and so he will sleep separately from us too. Wondering if it's normal for toddler to wake crying few times in the night? #pleasehelp #advicepls