Whines all the time with me, but not with other people - help!

Hi ladies, I was wondering if anyone had a LO who whines a lot with them, but is perfectly fine when other people watch them. My son is 11 months and I have always stayed with him. Since I'm a SAHM I'm literally with my LO 24/7 and my husband works a lot so he never watches him alone unless I run to the grocery store real quick. I've noticed he's been super whiny lately and I needed a little break so I asked my mom to watch my LO for an hour or two so I can run errands. I was so worried he was going to be awful, but she said he was great and never whined or fussed one bit. Is it just me? Anyone have any ideas 🤔