AirPlay / Chromecast / Miracast project screen from iOS / Android >> to MacOS ... not allowing to come through

I need advice on where to look to fix my network settings.

I got 2 machines - MacOS 10.14 and one MacOS 10.13.

10.14 is completely fine and can show external displays to it.

10.13 works fine and has no hardware or software issues but I can't connect to to project image wirelessly to it with AirPlay or Chromecast or Miracast..

Apps for Mac: Reflector (Squirrels) and AirServer; These apps basically running as servers to receive AirPlay/Chromecast/Miracast connections from other devices projecting the display.

I like how these apps work, they enable to project an image in a window on an existing screen. It allows me to work on the existing applications and see the projected image side by side. I need to project and Android tablet and Android phone to my screen.

Options I have reviewed:

• Vyzor, AirDroid and simiar: These are slow. EXCLUDED
• Teamviewer, VNC and similar remote viewing apps are slow. EXCLUDED
• Samsung Dex: looked promissing but it is being discontinued (I may still go this route of if I find no other solution): MAYBE (requires purchase specific Samsung devices)
• Samsung Smart View works on the 10.14 machine but not on this 10.13 machine which is what I need; (GOOD, but can't get it work)
• Chromecast works on the 10.14 machine but not on the 10.13 (GOOD, but can't get it work)

Samsung SmartView: Seems to me is more similar to Chromecast rather than Miracast (although they say it is build on this technology), because Smartview works fine for me, as does Chromecast, but Miracast doesn't... so this leads me to believe Smartview is more like Chromecast, maybe I am wrong

When testing Airplay connection, I was NOT able to project an iPad to Reflector/AirServer on the 10.13. So the issue is not related to Chromecast specifically. The 10.13 machine just doesn't accept any screenshare connections.

• Samsung SmartThings: doesn't work on MacOS and seems to be like overbloaded bloatware. THe problem is many devices come with this bloatware preinstalled. EXLUDED
• Scrcpy via USB or wirelessly ... looks promissing (GOOD, but can't get it to work)

Scrcpy: I am still installing it, for last 48 hours the installer is running with no end in sight (last installation couple of months ago broke and because it is such a pain to install this over Brew on Mac, I didn't try till now... still not getting anywhere (I will try installing Scrcpy over MacPorts but I am not holding my breath here,... it's an older MacOS machine)

• USB -C over HDMI - would work ok but I don't like the fact the projected image would be on a separate monitor. EXLUDED
• Chromecast dongle, Miracast dongle and similar hardware attachments: They would work but I don't like the fact the projected image would be on a separate monotor EXCLUDED
• Buy new iPad and new Macbook - Sidecar would be nice, but not an option, because I must use Android for an app exlusive on Android. EXCLUDED
• 3rd party dongles (similar to DisplayLink), same as above, they are projecting image onto separate monitor. EXCLUDED

I don't care about picture perfect quality, as long as the quality is acceptable. What I do care is the latency and slugisheness of some of the options.

Chromecast quality is acceptable and speed is good for me. So basically I have no option left but try to either fix this machine with 10.13 to allow the screenshare connections to it or to go with Samsung Dex.

Question:

What I need to do to get the network accepting connections on my 10.13 machine. I don't know where to start. Aside of advice like reset PRAM, fix permissions.. all done that. I am not considering at this point to restore the machine, hope I can find a solution by fixing the firewall settings, I assume that is the issue. But I don't know what to fix. The folks behind AirServer and Reflector are less helpful than I hoped with mostly generic advice.

Here is what I have done so far:

• Incoming connections are not blocked
• Tried to disabled firewall completely - didn't help
• Tried to switch between wifi and cable connection - didn't help
• Downloaded the AirServer Connect app to check the connection to the 10.13 machine and the app says "Unable to establish connectivity with AirServer ... The request timed out"

I do have LittleSnitch running and I have already played with that to see if there isn't a rule blocking, I don't see anything there. Tried to stop network filter but no effect.

Antivirus not running at this time, completely uninstalled.

I am wondering what are the typical things I need to look at to check, like ports and connections protocols and processes etc in case I can create manual rules to allow s connections if that helps.