Terrible 2

Dunno why now LO is 30 months old,she understands what we say but she will not follow and simply throw tantrums especially when I am around.when her dad is around she behaves much better. I am with her most of the time since I WFH and she only attends playgroup. So I don't understand why the person that spent the most time with her and yet she doesn't listen to me and keeps doing things I tell her not to. I already feel very stressed out due to new workload my boss throw to me. And now having to deal with the tantrums I feel really helpess.