Getting TRX to match TRX on Binance is likely tied to the monthly airdrop rate as defined here: https://support.binance.com/hc/en-us/art...
I'm guessing it has something to do with (spot price * estimated airdrop rate) trading too far from . Maybe even too close. Or because are trading above spot near a monthly airdrop snapshot. Much complicate. Such guess. Wow.
Binance is chosen as pricing source for its liquidity and earliest open date.
Sorry if I haven't replied to your message yet, I'm a bit backlogged :)