Hi,
I also have a similar problem. I bought a replacement battery for a MacBook Pro mid-2015 two years ago. The battery seemed to be working fine until a couple of months ago when I notice that when on battery, the charge goes from 100% to 90% and then drops to 7%. When I charge the battery up, the battery charges sequentially to 31% and then jumps to 100%.[br]
The battery now has 293 cycles and the battery condition shows as normal.[br]
I tried reseting SMC, disconnecting the battery, discharging and charging cycles, however with no avail.
Seems like a battery related issue rather than anything else.