They both make sense but "pose" is usually used to refer to a position you stay in without moving, while "position" could mean that you are moving. "Pose" also suggests something that's a little more intentional and something done for its own sake, like something you would do in front of a camera or an audience. Both sentences sound like you are standing or sitting awkwardly just so that you can get a signal, but "position" is probably the more correct word to use here. Of course, if you are standing in a position that looks like you were posing for a picture, and someone asked you why you were doing that, then "pose" would be correct here, even if you didn't do it for that reason.

Both are correct but maybe a little awkward. I would say: my wifi connection is bad. Sitting here helps the connection.

Strike the pose like Madonna in Material Girl i.e. make like an elephant, or a make like a fish Sit in a comfortable position: back straight; head up; shoulder back

No position has to do with place whilst pose refers to the way you are standing there, perhaps with your hand on your hip.

I think pose and position are not the same in this sentence. Position means the location you are in, but pose means the way you are waiting there :D