LT wants “Oh” to be followed by interpunction due to being an interjection even though the entire thing is an interjection.
EG1 “Oh yeah, the Chief wants to see us tomorrow at seventeen-hundred, right?”
EG2 “Oh yeah? Well, mine can go up to mach 5, how’s that for speed?”
another false positive would be “Oh well”.
EG1 “Oh well, guess dad won’t be staying after all.”
EG2 “Oh well, as long as the song is good, who cares about the cover-art?”
or “Oh BLEEP!”
According to most dictionary sites, using interpunction on “Oh” when it’s the first part of any 2+ word interjection (instead of being the whole interjection) is not proper grammar.