Shower leaking into downstairs wall

[ckl7]

Hi all.

Shower is leaking into downstairs when water is being aimed at wall .

All sealant has been redone on outside and between shower tray and wall at the bottom on inside , can’t spot any leakages here.

It runs down the wall downstairs beneath shower in lines , when water is sprayed at the wall.

Have a feeling it could be related to the screw holes not being siliconed before screws went into vertical rail, and it is letting water into them , then going down the wall?

Is the fix to take shower rail out and fill holes with silicone?

Or can I just put a thin line of silicone vertically up the inside rail, to prevent leakage through the screw holes.

I know you’re not supposed to silicone vertically inside due to water being able to drain back into tray, but would a thin line be okay?

I have attached the pics of corner where I think it is leaking through drill holes and also the leak into downstairs under shower

Any advice would be much appreciated