Why is it so ?

Heres my question. in the early mornings my uv filter attached to my fz150 leaves a gost/greyish effect to my pictures, as the sun rises it disapears ? also with the sun  low and when i have the uv filter attached an have a 1.4x canon tele converter at the same time the effect is gone ? no greyish haze, as soon as i take the 1.4x off it apperes but only when the sun is low. same thing happens with my macro converters d500/250.

cheers don

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another year has gone, just cleared my 200 gallery images will start all over again, thanks to everyone that took the time to look.