High blood pressure


So I am on bed rest due to high blood pressure. Ive been out of work and I don’t do anything too strenuous. I have to check it twice a day. It has not gone below like 145/90. But when they send me to the hospital to be monitored and I lay in bed for those couple hours, it goes down and is mostly in range. Anyone have that before and know why? Could my machine really be that off? The last time I went, I had it checked by 2 different machines and by a nurse in the family and it was all around the same but when I went in, it started to go normal and they just think my machine is wrong. Below you can see on two different machines