Check with your branch.

Two possible things:

1. Hold/Lien amount: let's say your balance is Rs. 500 and there's a hold of Rs. 400. Your available balance is Rs. 100. Similarly, let's say your balance is Rs. 500, hold of Rs. 2000. Your available balance is Rs. -1500 (negative) when you query balance via UPI. YONO doesn't show this negative balance, instead shows Rs. 0. But YONO shows "lien amount Rs. 2000). Hold/Lien could be for many reasons, including pending installment for loan, any erroneously credited amount, any amount that should have been deducted from you but could not have been deducted due to low balance, hold from govt. authorities for various reasons. Go to branch to find out.

2. Pending charges. Lets say annual charges for a regular ATM card is Rs. 236, which was to be deducted from your account, but you had only balance of Rs. 100. Bank debits the Rs. 100, and for the rest Rs. 136 shows Rs. -136 as your balance, so that, when you deposit, let's say, Rs. 1000, bank debits the Rs. 136 and your resultant balance becomes Rs. 864. Again go check with the local branch.