Got an alert when you posted @frivolous13 and thought I would follow-up. My dpi was set correctly and it still did not resolve the problem. However, re-installing and then re-booting seemed to fix the issue. Hope that's helpful.
Update: If I use the shortcut to open the KVM Window (the one w/ Quick Connect at the bottom) then open the settings, the options appear as before (sidebar option and list of computers). Still not so when opening from the system tray.
Windows Home 20H2 19042.746 Multiplicity 3.55 Build 00101.kvmpro KVM no longer has option for sidebar? It still has the "or" option, but nothing is shown. In addition, computers are no longer shown in the list that typically appears at the bottom of the page. However, if I use the shortcut (Ctrl + Shift + Left), computers are shown as before and I am able to view/connect. Restarting Multiplicit