Macbook Pro shuts down at 20% battery

Hello! I am currently using a Macbook Pro 15" Mid-2015 and I got the battery changed at an Authorized Service Provider this week because my cycle count was over 1000. However, when the new battery goes down to exactly 20%, the computer shuts itself down. When it happened, I powered it back on and the battery flashed as 20%. As soon as I entered my password to log in, it shut itself down again. When I plugged the charger and powered it back on, the battery flashed as 0%. Since I got my computer back yesterday, I have only charged it for 2 cycles as of today but I don't know why it keeps happening. I resetted the SMC and even ran Apple Diagnostics but the report came back with no problems found. What should I do?