Authorities saying the banking problem (in Sweden now at SBB after they soldoff at a loss an asset to raise cash) is due to depositors wanting higher yield on their deposits (since MFFs give like 5% apparently in US), and short sellers.

However, if banks are selling off assets at losses, which is like the thing they definitely don't want to ever do, is is just a case of shortsellers speculating, or something actually being there?

Why can't banks pay more for deposits (temporarily)? Why are they unable to do this? Funds are available to banks as long as they have collateral. They may have to pay a bit more than they want to to depositors but they don't have to lose them.