I'm considering investing in a long term rental or rental property for digital nomads either in Porto or Lisbon and would like to learn more from someone who is already invested in the market.

People that are good at branding and review designation can bury those low reviews and I wouldn't want to own someone's reviews but I am not your audience as far as a projected buyer as we purchased ours for a deal and they are both higher end beach stilt houses that are side by side and neither had been listed as a STR on any platform, we built it up with a direct book site and also use the platforms as well as the local website in the area to book. 

Quote from @Stephen Smith: Separately, a local roofing contractor was recently caught installing shingles on a BTC property in Cape Coral.  

That is a great place to start, as well as hitting some local real estate investor meetups so you can meet some other house hackers in person who have done what you want to do.

My local cable, internet, cell and utility companies are already using it to field calls and answer questions online and phone.

Before you jump into some type of mentorship (that they usually want you to pay for), I would start doing some meetups in your area with local real estate investors. 

Investing locally in the Bay Area will come with higher acquisition costs, but appreciation can still build wealth long term, so don't be weary if you're property doesn't cash flow right now the bat.

Only five of the qualifying 25 local cities saw a population decrease, topped by Bee Cave (-2.7%).

This is typically the slowest time of year for tenant placement, at least in our local market.

We took the reverse action and started lowering asking rents until they moved.I suspect the reason that one property of yours turned quickly is because your asking rent was very favorable vs. local competition.