andyv wrote:
My shower tray leaks at one corner where the metal framed glass panel
joins the wall. The leak reappears on the kitchen ceiling, but not the
bathroom floor.

No amount of sealing seems to work. I suspect the metal frame work
fills with water and slowly drains down after a shower.

I vaguely recall you should seal only one side of the base of the
metal frame.

Any tips?

The only sure way of sealing this is to take the whole thing off and re-seat
it again, or even better, buy a new one and fit that.
The chances are that when you remove it there will be a gap somewhere (maybe
in the tiles/joints or in the shower tray itself) and then you can do it
properly...IME many months / years are spent attempting to patch these
things up and all the while they just get steadily worse - any longer and
you may have to replace the kitchen ceiling, which also means a full
re-decorate of that room into the bargain.

On the plus side, you can claim on your house insurance if this is the case,
but only usually for the damage caused and not the actual fixing of the leak