How do I seal shower tray to floor tiles (Walk in Shower)?

Gorie

I have a walk in shower and at the joint where the shower tray meets the floor tiles (the tray is flush to the floor tiles) and between two floor tiles there are tiny gaps. I have to cover these with a towel when I shower otherwise when you step from the shower to these tiles water drips in. This has been present since I moved into the house, of course I only noticed a week later...

I have tried to fill them with silicone of many types (bathroom, external) however despite ensuring its super dry beforehand I cannot get the silicon to stay. It appears the gaps are too narrow for the silicon to really get into and grip (but of course its large enough for water I bet).

I have asked around and have been told to try a million things from grout, to different types of silicone to yacht varnish…

The bathroom is relatively new (although not fitted in the year I have lived here) and for now I do not want to take the tiles up and refit everything. Any ideas or suggestions would be greatly appreciated.

Thank You!