Hello, i currently own the M4 vs M5. which one have a better range???

Right now i have typically 280mbps internet but over wifi (computer connected to second mesh point via cable). From the second mesh point, i can barely achieve connection (via wifi) in one room of my house, the m5 would get around 4-10mbps while the m4 gets 60-150mbps.

my question is:
does the lower end m4 model but newer model m4 is better coverage than the m5. Is this normal??

how do i set up the m5 as the internet source when it has trouble sending signal to the outer points??