Waystones with no Suffixes negatively affecting loot drop rates?

I Vaal all my T15 waystones. After VAALing Some waystones end up having only prefixes and no suffixes. For example 100% rarity + 50% quantity, etc.

I save these "all prefix' waystones for the "Good" nodes. But I noticed any time i use one of these maps I get nearly no loot drops. I can tell something is wrong because all the white enemies dont drop anything (usually they drop gold), and even the unique map boss only dropped a single yellow item and a ton of blues. I walked out of many of these maps with less than half my inventory full after map complete.

I then tried a map with the opposite. Effectively all bad effects and only 1 prefix, 300% waystone drop rate, but no item rarity, no item quantity, none of the good stuff and used it on a neighboring map node (so they had the same precursor buffs on both maps) and i see normal monsters are dropping gold, bosses are dropping multiple yellows, and rares drop multiple yellows of the higher tier. I walked out with several portals worth of inventory.

I tried several of these "No suffix" vaal maps on really good map nodes and each time i used them I saw nearly no loot drop at all.

Just wondering if anyone else noticed this and whether this us just really bad RNG (it just so happens that when i used these "good" waystones i RNG into getting no loot on the map), intentional, or a bug?

It seems reasonable that better loot should drop from difficult maps though. But right now the display only says Waystone drop chance is affected by suffixes, but for me that doesn't seem to be the case?

I think this is due to the monster toughness affecting drops.

iirc it was since PoE Achnemesis league when they made this system where the amount of modifiers and effects that make monsters more dangerous directly affects their item drops.

This should probably mean that negative waystone mods increase the base lootdrops of monsters and the positive mods get then slapped ontop.

Without any negative mods on waystones there is no baseline loot to increase it seems.