I put in the borg deflector and my Bortasqu hitpoints doesn't increase. The borg deflector gives you +21 structural integrity bonus among other things.

So why it doesn't increase the hitpoints on my Bortasqu?

it has time delay.
Also: go to a system map, not sector space to check your stats.

Yep I checked in system map it doesn't increase my 43,500 hitpoints. My 43,500 hit points stay as 43,500 hitpoints. But I'll check again. Thank you. Hoping I was wrong.

Ah it seems I was wrong. Yeah my hitpoints increased from 43,500 to more than 46,000.

For a minute i thought it was another bug.

Stats are not updated instantly after equipment has been added or removed from your ship. . It can take upwards of 5 seconds before the UI stats are updated.