Earlier you weren't sure which version of the AC firmware you had installed. How did you determine now that you have 1.8?
Can you post the .txt file from your SD card? We may be able to see an issue.
Also, do you still use an iPad as your mobile device? Maybe try the new iOS app (2.8.3) released in the last day or so. There are reports that includes a fix for weak transmission signals on the P3 platform, though the app description was changed in some case to show only P4. AFAIK it has not yet been determined if the P3 is for sure included. It may or may not help you. It also may introduce another variable to the diagnosis, so keep that in mind.
This sounds normal to me. When you turn on the RC, the light is red because it is not connected to your AC. Once the AC powers up, the light on the RC switches from red to green and you then have control of the AC. You've had your Phantom since last year, correct? Has the light on your RC acted differently in the past?
Curious - is this the same P3 that you crashed that day you were teaching your wife?
Can you try to post a screenshot of your About screen?
You should be able to see this screen even if the app is telling you that there is an update available.
It looks something like this, though of course the versions should be different for you.
View attachment 55800