So the bug started out with an ENB error stating that the hardware forced anti-aliasing.
After fixing this issue in SkyrimPrefs.ini, the error no longer persists.
But one of the bugs that was brought over during that error is that Flames from torches, traps, and from spells appear transparent.

If it helps, I am running Vividian ENB, and here is my mod load order:
Skyrim.esm
Update.esm
SkyUI.esp
Racemenu.esp
RaceMenuPlugin.esp
Vividian - Torches Preset.esp
ELE_Legendary_Lite.esp
Skyrim Particle Patch for ENB - Flame Atronach Fix.esp
Vivid Weathers.esp
Vivid Weathers - Extended Snow.esp
DSerArcheryGameplayOverhaul.esp
Alternate Start - Live Another Life.esp

Can you see sun through walls?

Also: try adjusting intensity and curve under [FIRE] parameters, does it make any difference?

Since you're probably using the ENB weather plugin make sure to adjust in the weather window (or tick IgnoreWeatherSystem under [FIRE]).

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Embers HD
Smoking Torches and Candles
Particle and Subsurface Scattering Patches for ENB (updated 17/1/2020)
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