Each pockets is made with Bitcoin Core, with descriptor wallets.

In computer_1_online, synced Bitcoin Core 24.0.1, GUI:

• I create a PSBT from a watch-only pockets (descriptor: xpub1/xpub2/xpub3) of a multi-signature 2_of_3

In computer_2_offline,

• non-synced Bitcoin Core 23.0.1, GUI:
  • when I attempt to signal the PSBT with a pockets with one xprv (descriptor: xprv1, xpub2, xpub3), it exhibits “Couldn’t signal anymore inputs”.
  • when I attempt to signal the PSBT with a pockets with 2 xprv (descriptor: xprv1, xprv2, xpub3), it really works.
• non-synced Bitcoin Core 24.0.1, GUI:
  • when I attempt to load the PSBT, it exhibits the error “Unable to decode psbt readcompactsize() dimension too giant iostream error”.

What can I do to signal sequentially, one xprv at a time, a PSBT?

Thanks.