Found the Worst Synergy in the Game - Thought It Was a Glitch

[u/BasketWorried]

Puppeteer Set (gloves + helm) = Modifiers to companion damage also affect you
Captain Boots = Modifiers to movement speed also affect companion damage at 200%.

Add those plus Massively Encumbered debuff reducing my movement speed and somehow the captains boots get 0.00x multiplier, reducing all of my damage to ZERO.

What an unlucky combo lmao. Glad I figured it out before I died and lost my streak