Blue tooth disconnecting when not in view of the phone to engine. LC Remote works better???

BT is 2.4ghz, and it's pretty easy to block it.  I've had issues with BT when I'm in plain sight of the locomotive at 20 feet or so, so I'm not surprised it's an issue outside.

I don't know what version of BT the LC+ is running, but you could be running into multiple issues with the blue tooth.  The rocks could be blocking the signal, bluetooth from my experience with it can be blocked by any kind of dense material, not just as with Wifi where metal is the culprit. The other factor could be the range, newer versions of bluetooth are supposed to be good for (most bluetooth devices are commonly class 2, which has a range of 33 feet (10 Meters),but that represents under good circumstances (class 1 is 100 meters). So if you are a ways away from the engine and the rocks are there, both could be conspiring to stop you from communicating. The LC remote does not use bluetooth so it is very possible that the remote will work better, simply because it uses different technology that may be less susceptible to interference. 

One possible solution I can think of is using bluetooth extender/repeater technology, that for example in your case if the area where the rocks are would allow an intermediate repeater to take the signal from your phone, amplify it and resend it where it might be able to get through the rocks, or if the repeater is placed where it can still 'see' the engine and can 'see' your phone, it might work. You can't boost the power of the bluetooth signal from your phone as far as I know (maybe a clever hacker could do it, in a sense upgrading it from class2 to class1) so I would guess an extender/repeater may be the answer, though  I have never used one. 

Fairly close about 10 feet at the most away from it. We have taken down the height of the rock piles for now will try it out this weekend. Here are some shots of the set up.

I wondered how the repeaters would function, BT uses spread-spectrum frequency hopping, so the repeater would have to be a full BT device and connect on both ends I would imagine.

...connect IF they can too. The app may change some things about how that happens..?  (and I think does)

A better phone wouldn't necessarily help because of the loco's limits sending replies remains the same even if the signal it receives is stronger. And I don't think a better receiver would help quite  as much. 

Lionel chose the version of bluetooth that is limited to about 30 feet. There are newer versions that will exceed 100 feet which I have worked with and tested out. So, it's a design decision that we are experiencing with the current BT version.

Once again I ask the question... why isn't there an option in the software: "if it loses the signal, keep going at the last commanded speed?"  I'm guessing Lionel never expected this to be used outside at long ranges.  But there is no good reason why there shouldn't be an option like this in LionChief AND Legacy!

Outside at long ranges?  We were trying it inside with three different locomotives within about 15 feet and it couldn't keep a connection!

With respect to the "what happens when disconnected" question, Lionel and BlueRail took different approaches. When Bluerail disconnects, the loco keeps going at the previously programmed speed and stops when reconnected.  A Lionel BT loco will stop within 3-5 seconds of a disconnect. Could, of course, be reconsidered.

On that range question, we've had club members standing outside in the parking lot and running the BT trains at club meets.

In my range comparison checks, I found that with a specific loco the LC universal remote in BT mode will yield  greater operating range than the smart device app based BT. Not sure why this is so.

We took a bit of the height off the rock piles earlier in the week today we tried it out with a LionChief  Birthday Thomas. The little kids were given the remote today holding it fairly low about track level, the lowered rock piles did not disrupt the signal at all. But half way through the day a kid pulled Thomas off the track and after this what ever happened Thomas shorts out.

Hoping to get the folks that control the railway to allow a small fence to keep kids away from the tracks the little ones like to grab at the trains and throw gravel on the track.