Normally the rule of thumb with bonding is if you take a step forward and it’s not working, take a step back.
Sounds like your pair are just trying to figure stuff out, which is normal, but putting them back into completely neutral territory might help.
What often happens is the semi neutral area becomes less neutral as time goes, and becomes communal, so one bunny will often change its tune about sharing things the longer they spend there, and will begin to exhibit dominant behavior.
During bonding you should be continuing the pre bonding steps anyway-cages swapped toys changed, cages near each other etc, so if the fights are continuing I’d advise stress bonding sessions before putting them in a neutral area.
Do be careful not to leave them unattended for any lengths of time during this phase as it really is a very sensitive time-one bad fight and that’s the end of bonding for ~ 6 months
Also how big is the space? There is huge debate over this – some say use small space, others say as big as possible. There’s merits in each but sometimes playing with the space you give them can help change how bunnies interact