agree withKdv77kdv…you are overlaoding the textures.
IOS and browsers in general can not exceed a total load of 50MB.
After reviewing your textures…there is no real need for any of them at the resolution you have. All of these could be dropped to 512×512 or better yet get rid of them completely. You may only need one or two normal maps if at all….and your roughness and metallic maps should be deleted. If you have to have this just the way you have it.. I would suggested baking all the textures into one set of maps reducing your current count to no more than five.
Your triangle count is excessively high as well. Might want to optimize that mesh down a lot too…this should be under 100 triangles without much of an issue.
But the bottom line..you are blowing out the safari browser by overloading textures.