He is not everywhere, He is seated at the right hand of the Father and will be staying there for all time. Kind of like an eternal time-out. /SARC
Some people even in this life seem to have been favored with some preternatural gifts: deathlessness (Elijah and Enoch), bilocation (Abbess Mary of Agreda, Padre Pio of Pietrelcino), levitation (St. Teresa of Avila), infused knowledge (St. Jean Vianney, St. Joan of Arc), being able to change one's bodily form, and the like.
All quite inexplicable.
Bottom line: if even some saints while living in this mortal flesh, were able to bilocate, isn't it possible that the Resurrected Lord Jesus could omnilocate -- be at the right hand of the Father in Heaven, and at the same time be anywhere He chooses? Possibly in different forms? For instance, His Eucharistic Body?
After all, He's beyond the bounds of time and space.
Who's to say He can't?