I finally got out of this Connection Lost error loop after weeks of frustration. I already tried the obvious things like uninstalling the game and reinstalling it, other suggested workarounds, retrying over and over like it was the C-3PO event, throwing my phone down and yelling at it, etc. What worked was BlueStacks 5 for Windows 64 bit, emulating Android Pie. This allowed me to log into the game and hit the button to link my SWGOH saved game to the EA Connect software. Here is a short version of the steps that led to success:
ok
-Connection Lost Error Loop
-Went to EA web site and created an account
-Installed EA desktop client software and SWGOH for PC
-Still can't play because you have to hit that button inside the game to link to EA Connect
-Logged in to EA account on my phone by posting in bug forums
-Uninstall Google Play Games
-Restart
-Reinstall Google Play Games
-Connection Lost Error Loop
-Uninstall Google Play Services
-Restart Phone
-Reinstall Google Play Services
-Connection Lost Error Loop
-Play as Guest, Gear wheel Icon, Connect, EA Connect leads to a new error message that says "This is an error. [OK]"
This was the first sign of hope because I was getting a new error message I never got before and it was not a part of the loop.
-Install Bluestacks 4, unsuccessful, uninstall BS4
-Install Bluestacks 5, Android Pie
-SUCCESS got into the game for the first time in 3 weeks!
-Use the game interface to link to EA connect
-Logout of BlueStacks 5
-Login on EA windows app and play on the PC version
-Logout there and shut down computer
-Connection Lost Error Loop on phone!
-Play as Guest, Gear wheel Icon, Connect, EA Connect leads to a new error message that says "This is an error. [OK]"
-Play as Guest, Gear wheel Icon, Connect, IMPORT
That's IMPORTant because this option never worked before, but now, when I tapped Import it has my EA account name in there!
-Tap account name, accept, and it launched back into that familiar dusty cantina at last.
So that was the workaround fix, for me, at least.