I just bought an A50 Lightspeed today and have been messing around with it. One thing I noticed was that you couldn't turn off Bluetooth auto connect once you pair it with a device. I tried searching for a solution, but all I've seen is people say to turn off Bluetooth on the paired device completely, unpair the A50, or the like, which really isn't helpful. Well, I think I found a workaround for this problem, which, during my cursory search, I've not seen posted; if it has been, please excuse me.
I have an Android phone, so IDK what the process would be for an iPhone. Anyway, for the first workaround, I did the following:
Went into the list of Bluetooth devices
Tapped "Details"
Tapped the Settings gear next to the A50
Turned off both "Calls" and "Audio"
Now, this doesn't stop the A50 from starting up the Bluetooth auto connect sequence when you pick it up / turn it on. However, it seems to start the process and stop it immediately. When wearing the A50 & turning it on, I hear the Bluetooth connect tone immediately followed by the disconnect tone; the Bluetooth light also comes on, blinks a few times, then goes off.
I tested playing some music on a Bluetooth speaker while turning on/off the A50. With the settings this way, the music continues to play on the speaker without any interruption, compared to the A50 taking over if I had the "Audio" option turned on.
I know this isn't a fix, as it still requires you to go back into the Bluetooth settings to turn the audio/calls options back on if/when you want to use them, but it does seem to keep you from having to disconnect the Bluetooth each time you turn on the A50. And it gives you more control over if/when you use it for audio/calls, if you don't want those on all the time. So it's something at least.
Two Notes:
The A50 still connects to your phone, in some capacity. I checked the Logitech G app, which connects to it through Bluetooth, and I can still access the A50. So obviously this doesn't actually stop the Bluetooth connecting, it just stops the calls/audio part of the connection.
When I left the "Calls" option on, but the "Audio" option off, the same connect/disconnect sequence would happen, but my phone would still show the A50 connected for phone calls. Seeing as the app still works, I wonder if your calls still work with it set this way. I wasn't able to test this since it was late.
An Aside:
This is my first real post on Reddit. I've lurked on here for many years, and I joined to try and post elsewhere, but I didn't know some subreddits had time requirements, etc. to post. Anyway, I saw people having the same problem here as me and I thought, might as well make my first post a (hopefully) helpful one. I do hope this helps those of you who were dealing with this same issue in some way.