Welcome to the forum!
Most of us here are either ex-JWs or current JWs who aren't buying it anymore for a variety of reasons. Just so you are aware of your audience.
Now, on to your question. The anonymous NWT translation committee decided to "restore" God's personal name in the Bible, including 237 times in the NT where THEY believe it should be. Part of their reasoning is that if something is quoted from the OT (as is the case of Romans 10:13... it quotes Joel 2:32) and the OT verse has God's name (represented by the Tetragrammaton, which most other translations translate as LORD in all caps) then they would use it in the NT verse. Unfortunately, this rule is violated quite often for verses in the NT that are NOT quotes from the OT. They have a habit of translating the Greek word Kyrios into Jehovah instead of Lord.
If you have any interest in this, there is an analysis done around this that makes for an interesting read: