You are not able to interact with the Alien Base until flying away, then flying back again. Real pain if you want to do a last minute equipment swap, or save before entering a base but upon getting there.
You don’t need to leave alien base.
- click “Leave”
- click “Squad roster”
- edit load out in the way you want (it is bug that you can manufacture on board of Manticore)
- Return to geoscape
- Click first icon from the left “Dispatch squad”.