@clifford Welcome to the forum :slightly_smiling_face:
This is indeed explicitly stated in the rulebooks, see
Page 20, Europe 1940.2:
“Any industrial complex, air base, and/or naval base
located in the captured territory is now controlled by your
side (see “Liberating a Territory,” on the next page). If
you capture an industrial complex, you can’t mobilize
new units there until your next turn. If you capture a
major industrial complex, it is immediately downgraded
to a minor one. If you capture an air base or naval base,
you can’t use the added flight or sea movement or receive
repairs until your next turn.”
HTH :slightly_smiling_face:
PS
I have moved your questions to the appropriate forum category, as we have dedicated categories for every edition.