Think of what constitutes a person, one biological house (human body), the immaterial soul (emotions, will and mind) and spirit. Except we know from Scripture that multiple spirits can live inside the same housing.
The first verse is speaking of the fullness that LIVED (past tense) in the human house (the human biological machine that the second person of the Trinity incarnated into) and,
“Jesus answered him, “If anyone loves me, he will keep my word, and my Father will love him, and we will come to him and make our home with him.”
John 14:23
The second verse is present ongoing because the second person of the Trinity now residing in a new body, no longer a human biological, perishing, mortal body, but a heavenly body
“There are heavenly bodies and earthly bodies, but the glory of the heavenly is of one kind, and the glory of the earthly is of another.”
1 Corinthians 15:40
There are only two kinds of bodies in the created universe ( visible or invisible (think natural or supernatural))
God is spirit J4:24, and a spirit requires a body, be it natural or supernatural to manifest, many (plural) spirits can inhabit the same body, we have plenty of examples on the earth and now the second passage is telling us that heavenly bodies too can house multiple spirits.
Conclusion
Whilst Jesus was in a human body on earth, inside of Him WAS (past tense) the fullness of God, The Father’s, The Holy Spirits’ and His own Spirit.
[for those who take issue with the Trinity here is an OT example, God is speaking and He says God sent him, so God sent God and God sent His Spirit. That’s three right there.
“Draw near to me, hear this: from the beginning I have not spoken in secret, from the time it came to be I have been there.” And now the Lord God has sent me, and his Spirit.”
Isaiah 48:16
But this isn’t a debate about Trinity so don’t get hung up, see if in my analysis within the paradigm the verses conflict, if they don’t you can’t impose your paradigm on my analysis because they will automatically conflict]
When Jesus shed His mortal body and put on the immortal heavenly supernatural body, the Fullness continues to live IN Him or His heavenly housing. Because in this created universe order, a spirit, requires a body to manifest, whether that body is natural and subject to the laws of nature or supernatural and above the laws of nature.
John 1:14 remarks
Where is speaks about Grace upon Grace, think that John was conveying that they experienced Grace whilst Jesus was in the human house and upon that Grace whilst Jesus was in His heavenly house.
bonus verse
“If you had known me, you would have known my Father also. From now on you do know him and have seen him.””
John 14:7
The knowing and the seeing indicates in my mind from the Greek that the disciples were interacting with the Father (the Spirit of the Father) who was residing also in the human housing of the person Jesus of Nazareth. But they didn’t know it and Jesus was confirming that it was so