Can anyone recommend good companies to root cause  and implement solution to fix this issue?

Before throwing in the towel, exhaust every possible solution.

We ran into the same issue when we made our Costa Rica investments and didn't really find a good solution for a local mortgage there. 

The fear of unknown and the bad potentials, but then sh_t happens and ya remember that we got a choice to lay down and be done in by it or roll-up the sleeves and get to work and be a solution maker. 

Changing PMs is probably not the solution to your problem, and will likely create other problems. 

It’s a cleaner, more reliable solution, and while the higher subscription cost can feel like a drawback, it’ll save you a lot of headaches and time in the long run.

But if your budget is tight or your home only needs minor updates, your real estate agent can help you think outside of the box by suggesting simple DIY staging tips to help your home look its best.Bottom LineStaging your house properly can make it much more attractive to buyers, but it’s not a one-size-fits-all solution, and every home shines differently.

Now that you have the correct terminology, you can search for lots of potential solutions. 

Is replacing the HVAC with a completely different unit the best solution?

@Gary Abrams A cloud based solution would work really well in your scenario of having other family logging in and helping with management.