It's pretty far out of balance.
Some BMS prevent charge if there is more than 0.1v difference between cells, and you have more than that.
This is because a pack with this much difference usually has a serious problem with the group(s) that are that different from the others, and is trying to prevent a problem that could lead to a fire in cases where it's because of a badly failed cell, wiring fault, etc.
If you are certain the groups that are different are ok (like if they are the ones you replaced so they're at a different state of charge), you can see if the BMS (if programmable) has a user-changeable setting for this difference shutoff, and *temporarily* change it to rebalance the pack and fully charge it. As soon as that is done, you should change it back to the original setting, so it can continue to protect you as designed.
If the problem then crops up again, you will need to deal with whatever group(s) are then causing the problem, replacing as needed.
Note that a pack cutting off at half the usual capacity probably means that one or more groups in there are seriously degraded and should be replaced, if the pack started out perfectly balanced when you began the ride. If you checked the cell voltages at the shutoff point, the ones that are lower than the others are the cause of that particular issue--they've run out of juice.
If they weren't all balanced at the beginning of the ride, then you'd have to test by first making sure they all are exactly the same to start with, at whatever SoC you start at, then ride and test and watch cell voltages--any that vary lower than others under load are degraded and are only going to get worse.
