Step 2 of `Upload and Instantiate Contract` tries to read non-existent `flags.bits`

[rbochenek]

I am running two solochains based on different versions of Polkadot-SDK.
First one is based on Polkadot-SDK release-polkadot-v1.1.0 branch with pallet-contracts version 4.0.0-dev.
Second one is a much newer Polkadot-SDK stable2409 branch with pallet-contracts version 38.0.0.
Both are configured similiarly. I can upload, instiantiate and call contracts on both without any problems when using Polkadot JS Apps or cargo contract.

contacts-ui on the other hand doesn't work with the newer chain.
The problem occurs at Step 2 of Upload and Instantiate Contract:

It fails here:

contracts-ui/src/ui/components/instantiate/Step2.tsx

Line 143 in e5d63f5

const isRevert = flags.bits.toNumber();

It turns out the data returned from api.call.contractsApi.instantiate() differs between the chains.
Here's a comparison of result.result.asOk.result.flags.
Working polkadot-v1.1.0 chain:

Non-working polkadot-stable2409 chain:

Would appreciate any pointers on this one.