An Azure service that enables the connection of on-premises networks to Azure through site-to-site virtual private networks.
Hello @Abderrahim EL BRAK ,
Welcome to the Microsoft Q&A forum.
Based on a similar issue here. This is a known issue.
Can you try creating the connection using PowerShell? I was able to add the connection using PowerShell commands below.
$gateway1 = Get-AzVirtualNetworkGateway -Name <GWName> -ResourceGroupName <RG>
$local = Get-AzLocalNetworkGateway -Name <LNGName> -ResourceGroupName <RG>
New-AzVirtualNetworkGatewayConnection -Name VNet1toSite1 -ResourceGroupName <RG> `
-Location <Location> -VirtualNetworkGateway1 $gateway1 -LocalNetworkGateway2 $local `
-ConnectionType IPsec -ConnectionProtocol IKEv2 -RoutingWeight 10 -SharedKey 'abc123'
If you do not have a PowerShell environment set-up locally. You can try Cloud Shell to run these commands. Please let me know if you observe any errors. Thank you!

: I'm using a student subscription.