First Off .... Those are Tissue culture (TC) plantlets, not true banana pups. TCs are lab grown from green plant material. .... Pups are sprouts from a mature banana plant and usually 2ft or 3 ft tall when separated from the mother corm.
Now from your photo above the TCs have not even grown their true leaves yet and only have 2 pre-leaves. ( I forget what they are called). It obvious lab specimen hasn't been in plug trays every long, At this stage of growth the plantlets should still be in a shade-house (80%) or greenhouse under strict controlled growing conditions ( high humidity, heat, misting, grow lights, ect) for 2 or 3 months. Then moved to 50% shade-house for harding off to full sunlight. From TC to field ready, in ground planting would take about 6 to 8 months.
These plantlets are too young to have the reserve store of energy needed to recover from stress as you show in the photos.
I did a quick search for a TC growing description. This one and there are others you can google. Also, note there is a difference between TC plantlets and micro-propagated plantlets, but growing & handling is about the same after the plantlets get to the 50% shade-house stage.
https://www.agric.wa.gov.au/bananas/propagation-bananas
Read the 'Tissue Culture plant handling' section.