Indeed - it's not unusual at all. It's actually a blessing to have these matches to your mom.
On every given segment your mom has, one "side" of it is from her mother, and the other is from her father. So suppose, for example, you got the side of that segment of your mom's DNA that has your maternal grandpa's DNA, but these are your relatives on your maternal grandma's side - you're not going to match them on that segment, and therefore possibly not at all!
So it certainly IS significant - it tells you that your own segment there (the side you get from your mom) is for the opposite side of your mom's family from these other people. That will be more useful once you find out which side of your mom's family they're on.
Conversely, if you find out which side of your mom's family YOUR segment there matches, then that tells you that those guys are on the OTHER side. So you would only have to investigate the possibilities on half your mom's tree, instead of all her tree.
In summary, I concur. There's not only nothing wrong, but it's common - and useful information - once you get the hang of how this works. It can get a little tricky!