Your first payment is larger because your second payment is a fixed amount — that's the amount you were approved to defer. Whatever's left of your total bill is your first payment.
Example:
Your rent is $1,800
Your second payment is fixed at $600
Your first payment is $1,200 (the rest)
The good news: every month you pay your second payment on time, your second payment amount grows by 5% the next month — and your first payment shrinks proportionally. Over time, it gets closer to a clean 50/50 split.
So if you're at $600 / $1,200 now, next month you could be at $630 / $1,170. Keep paying on time and it keeps growing until you hit an even 50/50.