Not just you. Taskbar icons sitting out of position on a second monitor was reported against 2.74, and Neil confirmed on 24 August that we were looking into it and had not found the trigger.
His stated workaround at that point was to disable the enhanced taskbar, which avoids the behaviour until the trigger is found.
The honest cost of that workaround, because it is a real one. Centred alignment on Windows 11 is configured through the enhanced taskbar, so turning it off stops the icons floating and takes your centred layout with it. That is a choice between two things you want rather than a fix.
One route to avoid while you are looking. Going back to 1.55 does escape this, and Neil was explicit that it brings its own trouble with taskbar popups and with clicking taskbar buttons on current Win11 builds, which is why the newer versions exist. Not a trade worth making.
What I cannot tell you is where it stands today. That was a statement about 2.74 made in August, and nothing in the 2.8 changelog covers second monitor icon positioning, so I have no basis for saying it was addressed in the build you are on. Your report is a data point on 2.8 rather than something I can look up.