My Dupes will sometimes idle at the atmo suit check point briefly after returning, and if they deside to do another task outside the base they will leave without putting on a new suit. I am not running out of power or oxygen, and there are even extra docks with suits for when one suit needs repaired. There is also one floor tile after the check point then a door, and the printing pod is not inside my main base. If the dupe comes from farther away they put on the suit, this appears to only happen if they stand at the check point before going back out. This is on Vanilla ONI, not the DLC and was only noticed after the latest update.
Have dupes idle on the atmo suit check point after returning, then send them back out for another task.