Engine Play With Syzygy Tables

Greetings!

I'm curious:

I've only recently been introduced to Syzygy tables and I'm not certain I understand the exact effect they have on Engines. I think I get the DTM vs DTZ question; in that the Syzygy tables use DTZ to ensure that they are able to complete the game without drawing and therefore may not play the shortest sequence of moves to get to checkmate.

I have the 3-4-5 tables loaded; and as an experiment I setup a simple KBNvK position and had a couple engines (Stockfish 15.1 and recent Lc0 CUDA NN, don't have the version in front of me but just downloaded a few weeks ago) duke it out. I guess I expected to see the game complete extremely quickly--i.e., maybe not in the shortest possible moves but with quick moves, nonetheless--but instead they were as slow as the time control I gave them (with G/15+5 it was not unusual for the game to take a the full half hour; both sides often taking a minute or two per move). Now, yes, white always won; but it just didn't go the way I expected it to.

I also had one engine (Fire) that actually played Stockfish (Fire with the KBN, Stockfish with the lone K) to a draw, but I think the Fire engine may not have been reading the tables correctly. Not certain of that yet.

Am I misunderstanding something about how the engines use the tables?

If it matters I'm using Lucas Chess as my GUI (and just setting up engine tournaments with a set starting position), and my Syzygy tables are on an SSD.