Is your Electrum new?
Because I don't see any bech32 address (starts with bc1) in the outputs that's still unspent.
(Electrum versions starting March 30, 2021 will only create native SegWit wallets by default)
If it's created before version 4.1.0 when legacy address can be created:
The address is from Electrum's receive tab, so the address must be "unused" without a history, but every unspent output from that transaction have previous transaction history.
My conclusion is: You must have pasted the wrong address when you redeemed your voucher or you're using a fake Electrum.
The service where users redeem their vouchers is separate to the wallet, they can paste any coin/address there.