chlorophyll fluorescence is not as strong as fluorescence from sources like manmade materials (which often shine very brightly under UV). so most likely, your light source is putting off enough light in the visible spectrum that the reflected visible light is overwhelming the fluoresced red light. this is especially true if you’re using an unfiltered 395nm UV light, since the noticeable purple glow from these lights can easily overwhelm the red from chlorophyll.
i mostly use a filtered 365nm UV light for looking for fluorescence in nature. it produces only a faint light blue visible light, but even that little bit of visible light, especially if reflected back (or possibly fluoresced back as blue?) by waxy or cellulose-y (lignin-y?) surfaces can hide the red from chlorophyll. so things like mosses, ferns, and legume leaves are probably going to give you a more noticeable red than things like grasses and magnolia leaves.
it’s also worth noting that the chlorophyll fluorescence will fade in intensity over time, though this property allows you to do something like a sun print, which can be fun.
just for reference, in my area, the only natural thing that i’ve discovered that fluoresces with intensity on par with manmade materials are some millipedes (especially their legs), which fluoresce a bright bluish green. lichens are a distant second in terms of intensity, though they probably have the largest diversity of colors – yellows, oranges, blues, greens, and even reds. next in intensity are some of the fleshy caramel-colored mushrooms in my area that fluoresce green, and this is on par in intensity as the red from chlorophyll. there are other things that fluoresce, but they tend to be less common or tend to be relatively small structures / relatively inconspicuous.