Same thing happening on tiberian 16 since years. 100% sure it's a bug. When you attack a base in pvp... normally... you have 30 seconds to prepare your next attack... And you can strike immediately... to prevent
support weapons... But sometimes... after 2-3-4 attacks... the behavior changes and you see "post combat lock" Like if the game was thinking that you are attacking a forgotten base. So you can't strike immediateliy after the "Under attack by tou" You have to wait 30 stupid seconds... and be quick... if not... the guy can move. Here we are used to play with that bug... But because I saw a post... I decided to comment. This is totally random situation. And occurs on lvl 66 off against lvl 65 defs. Or any other off-def configuration.