compare 2 powers (Maxima 5.21.1)

Hello

I'd like to compare two expressions p1 and p2 with powers:

p1: (2^100+1)^(1/2):
p2: ((2^100+1)^2)^(1/4);
is(p1=p2);

--> Maxima says: false

but:
p1: (2^10+1)^(1/2):
p2: ((2^10+1)^2)^(1/4);
is(p1=p2);

--> Maxima says: true

Why does the first comparison end with the wrong answer?