If I have assets worth $110 today but they are locked up, and I have to pay back what I owe today, then I’m facing a liquidity crisis.
If I have assets worth $90 today, but $110 in a few years, and I have to pay back the money I owe in a few years, then I’m solvent and everything is good.
If I have assets worth $90 today, but $110 in a few years, and I have to pay back what I owe today then I’m insolvent.
It's insolvency if the current market value (not the hold to maturity value) of the assets is less than the liability. As far as I can tell though, SVB was solvent despite its losses, and just needed to raise money to cover reserve requirements after it realized the losses. What did it under was a lack of liquidity after everyone panicked and did a run on the bank, with 45 billion (out of ~175 billion in deposits) in withdrawals overnight.
It started as a liquidity crisis (do they had to start selling or raise capital), it turned into a solvency crisis (they had to sell even more therefore marking assets as available for sale which made them marked to market).
Right now SVB, if fully liquidated, cannot repay all of the deposits.
But a dollar in 10 years is worth less than a dollar today. In either case the result is the same: you take a haircut on the present value of your deposits.