Sounds like a video card related issue. Does your laptop have a solidworks approved video card? If so, install the most recent SW approved driver.
A few questions.
1 What os?
2 In control panel/display what do you have set for windows scaling?
3 What resolution is your laptop and 24 inch monitor.
I used to work with sw15 on windows 8, and I didn't face such problem. I wanted to upgrade to windows 10 and had to download sw16 (sw15 doesn't work under windows 10 although further on I found a parameter that allows emulation windows 8 I didn't check).
both resolution is 1920x1080
I was traveling so a little slow on my replies.
Open the settings app and go to System > Display, underneath the image of your monitors you should see a setting for "Change the size of text, apps, and other items:" What is this set at? It might say (100% Recommended).
Also, would you mind taking a SolidRX recording and sending the package to your Reseller? That will help us track down what is causing the issue.
I do have one final idea, depending on your display settings above.