Steps to reproduce on regtest:

```
converttopsbt 02000000000101ab73dba46508bacdb49a988ddd74bc9d39c9cb7e057af060ca8c6b6861e28e3c0300000000feffffff02b828d0b20000000017a914d1954862afd728fbb055149002958e1d1b9e1f0b8700ca9a3b0000000017a91442170ccb3441cff1723af9afab6f2553103e1d578702473044022077380c6e16496d9905aef120694c329be51522847cb5d53fa74b94698c95678d02202d32c46e0e17420a83dee830fefda7d40529182f5d82be47c2b49a7b83214ab50121026d483d6628dcc3ef6e3ab9ed4937c452c263c7e0ac80eb4be97426d5da8f640500000000
```
or 
```
converttopsbt 02000000000101ab73dba46508bacdb49a988ddd74bc9d39c9cb7e057af060ca8c6b6861e28e3c0300000000feffffff02b828d0b20000000017a914d1954862afd728fbb055149002958e1d1b9e1f0b8700ca9a3b0000000017a91442170ccb3441cff1723af9afab6f2553103e1d578702473044022077380c6e16496d9905aef120694c329be51522847cb5d53fa74b94698c95678d02202d32c46e0e17420a83dee830fefda7d40529182f5d82be47c2b49a7b83214ab50121026d483d6628dcc3ef6e3ab9ed4937c452c263c7e0ac80eb4be97426d5da8f640500000000 false
```

Further reading: #13738
flags |= WALLET_FLAG_BLANK_WALLET;
    }
    WalletLocation location(request.params[0].get_str());
    if (location.Exists()) {
        throw JSONRPCError(RPC_WALLET_ERROR, "Wallet " + location.GetName() + " already exists.");
    }
    
    if (!CWallet::Verify(*g_rpc_interfaces->chain, location, false, error, warning)) {
        throw JSONRPCError(RPC_WALLET_ERROR, "Wallet file verification failed: " + error);
    }
    std::shared_ptr<CWallet> const wallet = CWallet::CreateWalletFromFile(*g_rpc_interfaces->chain, location, flags);
    if (!wallet) {
        throw JSONRPCError(RPC_WALLET_ERROR, "Wallet creation failed.");
    }
    AddWallet(wallet);
    wallet->postInitProcess();
    UniValue obj(UniValue::VOBJ);
    obj.pushKV("name", wallet->GetName());
    obj.pushKV("warning", warning);
    return obj;
}
static UniValue unloadwallet(const JSONRPCRequest& request)
{
    if (request.fHelp || request.params.size() > 1) {
        throw std::runtime_error(
            RPCHelpMan{"unloadwallet",
                "Unloads the wallet referenced by the request endpoint otherwise unloads the wallet specified in the argument.\n"
                "Specifying the wallet name on a wallet endpoint is invalid.",
                {
                    {"wallet_name", RPCArg::Type::STR,  "the wallet name from the RPC request", "The name of the wallet to unload."},