After changing clothes without dropping what You had on, you can't move you can't interact with them via inventory menu for a few seconds.

Hospital in Chernogorsk almost always but not everywhere mostly on 1st floor(not ground floor) when changing clothes (Scrub T-shirt to Hiking Jacket) without dropping what You had on, the clothing You had on will go underground and won't show in vicinity tab but you can still pick it up via F interaction.

Those 2 bugs might be related since not every piece of clothing is affected by the 1st bug and the 2 pieces of clothing from the 2nd bug are affected.