No one has mentioned ShareMouse yet? (https://www.sharemouse.com/) In my experience it has worked way better than Synergy. I switched after getting fed up with the synergy developers not responding to various multi-year old bugs that made the software unworkable for me (e.g. https://github.com/symless/synergy-core/issues/5992).
The only downside is that you have to "renew maintenance" to continue receiving updates to ShareMouse after a year. But I haven't done that yet and it still works fine for me.
The only downside is that you have to "renew maintenance" to continue receiving updates to ShareMouse after a year. But I haven't done that yet and it still works fine for me.