Hear me out. At its worst is an hypotesis so lets keep an open mind.

Einstein theory of relativity sais that time variates based on the speed and the reference. However his analysis relies on the fact that the speed of light is constant. Which is a given since Maxwell. But what if Maxwell’s equations are wrong? It would keep the theory of relativity valid however its the light that has variate speed and time remains the same.

For example: me moving at the speed of light looking at the railstation clock as i depart would not show me the time stopped, it would actually show me an apparent time stopped as it is the last reflection that reaches my retina. It can indeed be seen as time moves slower but out perception of time was based on the fact that images are processed at the receiver. So if we get ilthe image slower we assume time is slowed, but it might mean that the reflection of light in the railway clock has yet to reach the observer. As in time is constant, speed of light differs.