JoyCons only work when attached

You could install atmosphere

 

Atmosphere does, and sx supports 11.0 by the way. SX is outdated now, however, which is why switching to atmosphere is a good idea and may fix your problem

 

Have you tried pairing them from within the switch joycon settings
Do the little lights flash on the joycon side rails when they are detached from switch
Also try and pair them to a android mobile phone or your pc
Good way of testing

 

Have you given them a good charge at least 24hr on the dock

 

Did you check if the console have the airplane mode enabled?

 

In regards to charging, the Switch works like this:
- Console charges though USB-C cable and without dock, but joy-cons don't.
- Battery-drained joy-cons not charged in the dock will work only if attached to the charged console, as they will use console's battery to work as a portable, but won't work unattached from the console without being charged in the dock with console or on a dedicated joy-con charger.

If you haven't tried this yet, just charge the console in the dock with the joy-cons attached in order to also charge the joy-cons or use a dedicated joy-con charger as an alternative.

Not sure if this is the solution for your problem, but I hope it makes sense and helps you somehow.

 

You mean, joycons only charge on dock, and they dont charge when console is plugged to AC with usb-c charger?

I would like to know if is there any way to prevent the console from auto power on when connected to a charger.

 

Yes, that's exactly what I mean... It's weird but that's how it works.

What do you mean by "auto power on when connected to a charger"? It may power on, but you can always switch it off once you have the charger connected and it shouldn't do it on its own again.

 

This should explain why my joycons are always drained!

When my switch is also drained, I plug it to AC charger. It auto powers on. I think this is an idiot behaviour. None of my other devices do this when plugged.

Sometimes, after long period of drained battery, the switch blinks the screen and dont charge. Do you noticed this?
I have to charge it on RCM to stop the blinking!!!

 

I had the same problem. I had to change the ribbon flex cable of the joycon to fix the sync issue. Be sure to get the correct ones (left joycon or right joycon)

 

I had this issue also! I got flex cables from AliExpress for like $3 to fix it

 

Do you have an emuMMC?

 

I'm having the same problem. I recently migrated from SX to Atmosphere and my joycons only work when attached to the console both on emuNAND and sysNAND. I've tried pairing them again and they still won't work when unattached.

 

Joycon has it own firmware you can try updating that see if that fix anything.

 

I'll give it a shot.

 

Migrate if you want but SXOS is not the problem. Also, for the record, SXOS is compatible with 11.0 and all current software. If i were you i would update your EmuNAND to 11.0 and keep it around so you can still use USB loading if you want. You can backup the EmuNAND. Keep it on your PC. Or you can have 2 EmuNANDs on the same SD. You could have a separate card as well. One for Atmosphere and one for SX. Don't expect it to fix your joycon issue. Atmosphere has no XCI/USB loading.