Block Attempt after modifier is played.

Hi, good night.
I have a question that perhaps it is answered in other topic, sorry for that in advance.
The question is:

Player A bleeds Player B with a Govern. B declines to block. A plays a conditioning. Can B try to block or he can only deflect because he declined to block the bleed before the conditioning was played?.
Easier and as a general rule: can I try to block an action that I declined to block (No Block Attempt) after any modifier is played?
Thank you.

When player B has declined block he may not block after action modifier to make the bleed bigger has been played. Player B may still play reaction cards like reduce or deflect.

But if he deflects and it comes back he gets a new window for blocking.

Correct.