Hey @Wheelzup,

The power connector should not require any additional force to be connected.

Would it be possible for you to contact our team at ussupportteam@tp-link.com with pictures of the cable and brick, along with a proof of purchase? We would like to verify that your device came from an official source in case it is not the correct cable, so that we may provide support.

  @Wheelzup 

You should not use any excessive force to plug the power adapter barrel into the switch power port.

For TL-SG108E the power barrel should be measured 3.5 x 1.35 mm according to this table.

It should look like this:

If your power adapter barrel is the most popular size 5.5 x 2.1 mm, that's the reason you can't plug it.

  @Wheelzup

It's reasonable to request some photos and the receipt for identifying the problem. Did you measure the barrel outer diameter ?

But while waiting for an answer, why don't you contact the retailer (Amazon) with the issue description and check what they'll say.