the bib
Nowhere in scripture does it say he does not now sit upon His Throne of Glory.
But scripture does say this Zech 6:13
13 Even he shall build the temple of the Lord; and he shall bear the glory, and shall sit and rule upon his throne; and he shall be a priest upon his throne: and the counsel of peace shall be between them both.
The Temple of the Lord being built here is this One Eph 2:21
In whom all the building fitly framed together groweth unto an holy temple in the Lord:
Zechariah 6:13 refers to a temple ON EARTH not in heaven. No temple has to be built IN HEAVEN. His reign is where his temple is and that is ON EARTH and he does not come to reign on his throne ON EARTH until Matthew 25:31.