I bought two Anker Soundcore Boost (model A3145013) from Amazon to pair with each other.
Unfortunately, this “wireless stereo pairing” does not work as described. Each speaker works individually.
If I press the on/off button of both devices at the same time for a few seconds, they flash for about 1 minute and then go off.
Although both speakers are displayed as “actively paired” in the smartphone’s Bluetooth device overview, music only comes through on one of the two speakers.
Unsure as I do not have this item but the soundcore help section may have some video on it.
Unsure of your pairing technique
Most devices I know for soundcore, you are initially pairing one speaker and then you can pair the second speaker afterwards.
Shouldn’t it be the bt button, after both speakers are switched on?
I’d suggest making sure only one is connected to your phone device. This may mean forgetting the second speaker on your phone, and trying the speaker to speaker pairing process again.
You didn’t specify if on iOS or Android, but either should allow for renaming of your speaker on your phone. I’d suggest naming the main one different than its regular name to help to identify which is paired up…
Good luck, keep us apprised of your testing…
Thanks for all answers. Finally I found the TWS-Button and now it works
Oh TWS button!
Seems a new feature on these speakers.
I had an “old” one some time ago, but only one!s
So I was never forced to connect with another one.
Enjoy the TWS sound. 
I use my 2 little Flare mini it this stereo mode.
GREAT!
Best for classical music in a 20 sqm room. 
Glad you got it working
Glad your issue solved.
Thanks for letting us know, perhaps you could add a photo or two of the elusive button?
Hallo, habe heute den Soundcore Boost bekommen. Musik über Spotify alles ok, bekomme ihn sber nicht in die App integriert. Gefunden wird er aber, auch neu koppeln, ein/ausschalten… nichts hilft. Mach ich was falsch ?
Grüße.
Piet
Hallo Piet,
OK!
Mach mal Folgendes :
Lösche den speaker von allen Geräten.
Dann versuche den mit der app zu verbinden.
Wichtige ist eben, dass der Lautsprecher nicht in den bt-Listen von anderen Geräten vorkommt.
Dann durch das Drücken des BT-Knopf auch beim Lautsprecher alle gespeicherten VFerbindungen
löschen,
Sollte klappen,
Frohe Ostern aus München.
Franz
PS. I am too busy to write that all in Engish.
Have to care for our meal.