Bizarre shader bug with portal 1

Earlier than I clarify the difficulty:

My cellphone is a Google pixel 9 professional xl operating android 16.

Now, I put in (or tried to) portal 1 utilizing the supply engine port discovered within the discord for nillerusr port of supply for android, and I needed to play portal 1 on my cellphone, so I downloaded the engine from the information, and put in what I believed I wanted, copied over the portal recordsdata from steam on my PC into my android cellphone inner storage > srceng excluding the bin folder, and ran the sport, the principle menu appears to be like superb, however then I’m going into the primary chamber and it appears to be like like this (screenshot offered)

Any and all assistance on this matter will likely be enormously appreciated.