The problem is that you are just not getting the joint hot enough.
Silver is an excellent thermal conductor (the best of all the
metals), and the large bracelet is sucking the heat away from the
joint faster than your torch can put it in; net result is that you
can't get the joint hot enough to melt the solder.
It's clear that your flame is hot enough, otherwise you wouldn't be
able to solder at all, but it's just not big enough to generate
sufficient heat to get the bracelet hot enough to melt the solder. A
cup of hot coffee contains more heat than a red-hot needle, even
though the needle has a much higher temperature. Your torch flame
generates a certain amount of heat at a particular temperature. As
you play the flame on the bracelet, the heat enters the silver and
the temperature starts to rise, but it also leaks into to the rest of
the bracelet. When it reaches the edge it starts leaking into the
air. If your flame can't deliver more heat than leaks away then the
temperature at the joint won't rise any more.
Insulating the bracelet to minimise loss of heat to the air helps,
as does surrounding it with fire bricks to reflect heat back. A
larger flame, or a very much hotter flame will also help. The best
thing to try is a bigger flame and surround the bracelet with fire
Regards, Gary Wooding