Ominous banners saved in the Saved Toolbars will not get picked up by raiders as the banner could have existed in a different version before the full release of 1.14.2. As shown in the attachment video, 2 ominous banners also didn't stack. One of the banners were in the Saved Toolbars while one was pick block after I placed the banner (from the toolbars) down and dropped the original one from my toolbars and picked up the one that was pick block.

Could possibly be related (or duplicate) to: MC-140565, MC-152035, and MC-151793.