Unlike 1.19.2, in 1.20.1, [Improved Tooltips] -> [Attribute Tooltips] seems to be independent of [Improved Tooltips]: [Improved Tooltips] can not control if vanilla attribute tooltips be hidden, only [Improved Tooltips] -> [Attribute Tooltips] can control it. It affects attribute tooltips for equipment and potions.

Mod List

1.19.2

[Improved Tooltips] Enabled

Display improved attribute tooltips normally

[Improved Tooltips] Disabled

Display vanilla attribute tooltips normally

1.20.1

[Improved Tooltips] Enabled

Display improved attribute tooltips normally

[Improved Tooltips] Disabled

①Not display vanilla attribute tooltips. Holding shift still make vanilla attribute tooltips display normally

②But if you restart game while [Improved Tooltips] Disabled, you can see vanilla attribute tooltips come back. However, [Improved Tooltips] -> [Attribute Tooltips] not work, while it's 'true' in q-button config.
② was discovered accidentally after restarting the game.

[Improved Tooltips] Enabled/Disabled, while [Improved Tooltips] -> [Attribute Tooltips] Disabled

Display vanilla attribute tooltips normally

This issue was fixed in Quark-4.0-460 with Zeta-1.0-20. The following commit may have fixed this issue.
VazkiiMods/Zeta@release-1.20.1-1.0-19...release-1.20.1-1.0-20
release-1.20.1-4.0-459...release-1.20.1-4.0-460