The only parallel connections are - , + and the BMS connections, my concern is some current must be flowing through the BMS wires between the 2 parallel cells of cell 12.
How did you measure this current flow?
If it hasn't been measured, what leads you to think there is current flow?
If the series connections are correct and equal, the parallel connections are correct and sufficient, and the cells are equal, there won't be any current flow between parallel cells, as they will be a single cell to the system, electrically.
If there are no parallel connections between cells other than tiny BMS wires that have high resistance, then if the paralleled cells are not identical, current flow thru the system creates voltage differences between them, and current would flow, there will be voltage differences across the resistance of the paralleling wires.
The BMS then does not read the actual cell voltages, and cannot respond correctly to problems in the cells.
As for the differences between cells, whether it will be a problem depends on how long you can and need to leave the battery on the charger for every cycle, so that it can rebalance the pack, and how quickly the problem grows worse (since differences will nearly always get worse with time and usage; the harder they're used the faster that usually happens).
Note that BMS with a cell-delta protection limit function would normally shutdown a pack that has a tenth of a volt difference between cells, as that indicates a serious difference between the cells' characterisitcs, whcih usually indicates a problem with the cells that are that much different from the others. Some BMS with this function have a programmable value for it, or even the option to disable it...but it's a good function to have since it warns you that the pack is approaching a serious problem or even failure. Whether it matters to the BMS if this difference exists only during current flow or is there all the time, probably depends on the BMS design.