Apple didn't start restricting the battery health information upon replacing the battery until the iPhone XS. Prior to that there were no restrictions on a replacement battery, so it's not going to be related to just the fact that you replaced the battery.
As @samm_ has stated, you'll need to open the phone back up and check the battery connection. Unplug it and check it with a magnifying glass and a bright light; both the connector on the flex cable and the one on the logic board. You're looking for bent or broken pins or possibly any kind of contaminant that may have gotten into the connector and is keeping the battery pins from making contact.
Once you're satisfied everything's okay, clean both sides with 90% or higher concentration of isopropyl alcohol. Once it's dry, reassemble and retest. Look at the battery health in the settings and if the phone indicates it's charging when plugged in.
If you still can't get anywhere, then you may indeed have a bad battery. If you still have the old one you could try swapping it in; if it works at all, then that would tend to point to the replacement battery being at fault. Given that they're not all that expensive, you could always try getting a replacement; you can try getting one from the original seller or just try something completely different and buy it elsewhere.