Into my 4th season and have quite a good team ratings overall wise. Slightly struggling going into conference play and I think it is because I give up way too many offensive rebounds

Obviously we have the offensive and defensive rebounding stats. However, I was wondering if anyone has run into the issue where they don't have have anyone or (1/2) decent rebounders. I use 9/10 defensive glass crash with a 2-3 zone as my primary half court defense. Only issue is I am still giving up 10+ offensive rebounds per game.

Will changing my half court defense give me more chance to rebound the ball? If so what suggestions

Yes. Zone defenses will give up more offensive rebounds unless you have really good rebounders. When playing zone your players are not in a good rebounding or blocking out position so you typically give up more rebounds as a result.
Man to man is better for rebounding. But you may still need to use zone based on your team.
Be careful setting your offensive crash boards real high as you may find you give up a lot of fastbreaks to a more athletic team than you. This may be why you have trouble in your conference, take notice of how many fastbreaks you are giving up or scout the other team and adjust your crash boards accordingly. I typically start a game with defensive rebounding at 6 or 7 and offensive rebounding at 5 and watch rebounding stats and how many fastbreaks the opposition is getting and make adjusts around the first 7 to 10 minutes into the game and then again at half time to try and keep rebounding equal or better than my opposition. But I also play 90% man to man defense.