Welcome to the forum and sorry to read about your problem. It is truly frustrating when that happens, but the reasons could be that the app in your Samsung is already 1 year old (a day can be a lifetime in the compatibility of an app) and the problem lies there, or that SBS made a change that affects the app in your Samsung but not in the iMac. Computers and tablets and phones and even apps in PVRs tend to be more robust and longer lasting than those in TVs. The worst of it is when there is a worry with a TV it is common that nobody wants to know and help.
If the reboot, unplug, blah blah doesn’t fix it one should go the the vendor’s (in this case Samsung) support, or user forum and hope someone else has the problem. Also check for updated firmware for your model. Note that sometimes updates fix things, and sometimes they can break them, too. Good luck getting it sorted.