Hello,
Sorry to say but it seems that you have 2FA enabled on your Site which is why after adding Login details we are unable to proceed further as it was asking for 2FA Authentication Code.
Regarding your mentioned concern, please navigate to your Header Builder and there edit the Menu element in which you are facing the issue and once check if you have enabled the Display inline toggle option or not: https://snipboard.io/HF1kfC.jpg
If you have enabled it already and still you are facing the issue then please try using the following Custom CSS on your Site:
.wd-header-nav {
flex: 0 0 auto !important;
}
Location to paste Custom CSS, go to Dashboard >> Theme Settings >> Custom CSS >> Global CSS section >> paste the CSS.
Best Regards