No experience with that specific brand, but batteries can fail to meet specification for several reasons. Most commonly one cell group gets out of balance and triggers early shutdown. This could be from a defective cell or from a defective BMS.
The only way to test is to open the pack to where you can measure the individual cell group voltages.
About the only other thing that might help is to try a balancing charge. If one cell is just low, but not defective, you can sometimes just charge long enough to get it balanced. Some chargers cut off too early to make this easy, some chargers you could just leave on charge for a few days and do it. The balancing process is very slow at best. With chargers that cut off early, the approach is to charge until cutoff, then discharge just enough to get it to charge again, then repeat the cycle many times.
If the pack failed from the start, you can claim it was defective and ask for a replacement.
"One test is worth a thousand opinions"