Sadly it's hard to provide an exact test case, since I do not exactly know which factors contribute to creating this situation.
I've made Prax 0.5.3.3 available to you, and
here's my INI file and a savegame of a very busy Prax game (five Mega CPUs and me all on the same team with ~1000 total units). Before I saved this savegame, an archer on the red bottom center settlement was boosted, with no unit or structure anywhere nearby which could cause it. Sadly, when you restore this game, this is no longer the case.
However, after restoring this game i just moved a large mixed group of fighters (hunters / Jaeger (bow/arrow unit), axemen / Axtkaempfer, spear fighters) back to the red main base on the top left where a tower is (boosting the hunters), then deselected them, reselected them and some other fighters and moved them back to bottom center. As a result, one of the hunter units remained boosted (with feet icon and faster running) well beyond the towers' range.
I then repeated this with two groups of fighters including many hunters, moving them into the towers' range, deselected them, reselected and grouped them, and moved them out of range again. To move them out of range, I just right-clicked on the mini map, then deselected them before they moved out of the towers' range, and pointed the camera elsewhere. When they finished their march to bottom center, several of the hunters were still boosted.
I understand how this may help to reproduce now, but hardly helps finding the cause. So I'll try to reduce the test case next, and report about those observations.
Edit #1:I've got a
slightly more simplified test case now. A single player Prax 0.5.3.3 game where you produce roughly two dozen archers, kill the spearman you had from the start, and only have the necessary buildings (center, smithy, farm), no upgrades, on the "6players" map. Moving as many of those hunters as you can grab to the center of the map by selecting them then right-clicking on the map will result in some of them remaining boosted although they are well outside of the towers' range.
Edit #2:What may or may not be relevant that, using the "Edit #1" test case and moving the group of archers back and forth, it turns out those which remain boosted vary, while some of them remained boosted (when they should not) repeatedly, there were either others who had been in the last run but weren't in this, or new ones which had not incorrectly remained boosted during the last run, but now. So it does not seem to be related to low/high unit/object ID.
Edit #3:Another observation is that it does
not matter whether or not you follow those hunter units with your camera, it will happen either way. In fact with this test case it is reproducible for me every time I move those hunters out of range. And after a while some of the workers will also run into the problem, having the feet icon when they should not.
Edit #4:Test case further reduced. Now we only have hunters, enough cows to survive, and the tower. Even the sorcerer is gone, so only one source of an attack boost is left.
With this setup, I can not reproduce the issue while moving the group (key 1) of archers to the right (maybe because of the trees they run into there), but almost always when I move them to the bottom of the map. Some hunters will remain boosted most of the time I move them there.