Finalize input for merged psbt. ‘Unable to finalize input #0’

Here’s a scenario: UserA(bc1pmd3tdzucfnpmq2m3d82yzqmht6hp7smfc2g0tze6ywkxn6h258aszxjdn6): I would like to sell the inscription. (5d8c42c867f9c09c0a44397ad2c91d73e8ebb7734e75f54f7caba8ea95eba3b6:2) he uses ighashType to sign the psbt. SIGHASH_Single | SIGHASH_ANYONECANPAY available
This is UserA’s signature:

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

Anaizepsbt(userA’s signature) =>

  "inputs": (
    
      "has_utxo": true,
      "is_final": true,
      "next": "extractor"
    
  ),
  "estimated_vsize": 112,
  "estimated_feerate": -0.00000892,
  "fee": -0.00000100,
  "next": "extractor"

UserB wants to buy this, so he signs the psbt using SIGHASH_ALL:SIGHASH_ALL. UserB’s psbt before signing:

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

This is UserB’s signature.

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

Anaizepsbt(userB’s signature) =>

  "inputs": (
    
      "has_utxo": true,
      "is_final": true,
      "next": "extractor"
    ,
    
      "has_utxo": true,
      "is_final": true,
      "next": "extractor"
    ,
    
      "has_utxo": true,
      "is_final": false,
      "next": "finalizer"
    ,
    
      "has_utxo": true,
      "is_final": true,
      "next": "extractor"
    
  ),
  "estimated_vsize": 576,
  "estimated_feerate": 0.00049000,
  "fee": 0.00028224,
  "next": "finalizer"

(The 3rd input is UserA’s encryption, so it is not confirmed)

Merge the signatures of UserA and UserB (copy UserA’s inputs(0) signature into UserB’s inpust(2) signature):

(buyerSignedPsbt.data.globalMap.unsignedTx as any).tx.ins(2) = (
      sellerSignedPsbt.data.globalMap.unsignedTx as any
    ).tx.ins(0);
    buyerSignedPsbt.data.inputs(2) = sellerSignedPsbt.data.inputs(0);

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Analizepsbt (merged signature) =>

  "inputs": (
    
      "has_utxo": true,
      "is_final": false,
      "next": "finalizer"
    ,
    
      "has_utxo": true,
      "is_final": false,
      "next": "finalizer"
    ,
    
      "has_utxo": true,
      "is_final": true,
      "next": "extractor"
    ,
    
      "has_utxo": true,
      "is_final": true,
      "next": "extractor"
    
  ),
  "estimated_vsize": 576,
  "estimated_feerate": 0.00056000,
  "fee": 0.00032256,
  "next": "finalizer"

I find this result very strange because the default psbt for this merge is UserB’s signature. But somehow the merge process changes the validity of UserB’s input signal. When I try to finalize my input, I get the message ‘Unable to finalize input #0’.

Any clues?

thank you so much