We have investigated this and found a design issue: When the user clicks the submit button, the browser blurs the bank data field (triggering an onBlur event) before triggering the onClick event. In the sub-second time scale between the blur and the click event, the browser renders the BIC field, moving the buttons further down. This leads to the situation that the browser somehow 'loses' the click event because it's in an area that's redrawn. If we use visibility instead of display for the BIC field (reserving whitespace, but hiding the element) the error does not occur. However, this looks kind of ugly:

We probably need to involve UX to find a more elegant way to make the submit button stay in place.

The other solution to this would be to avoid the blur-triggered asynchronous validation of bank data and validate it on submit. Be aware however, that the user then would have to trigger the validation manually in order to convert old payment data or show the BIC. This would also affect the donation form where the background validation and showing of the BIC is fine.

https://gitlab.com/fun-tech/fundraising-app-frontend/-/merge_requests/28

deployed to https://testing05.wikimedia.customers.manitu.net

• The reserved whitespace between the bank data component and the summary is too large.
• Bulma is setting the height of the bank name line to 20 or 25 pixels depending on the visibility property, resulting in a little bump when changing this property.

tackled those 2 issues,
please have another look, I redeployed to https://testing05.wikimedia.customers.manitu.net

deployed abban's latest changes to https://testing05.wikimedia.customers.manitu.net

Looks good to me.