This is a side effet of a chrome update that has been scheduled for a fix, by the google team on the next week, 12/12/2022: https://bugs.chromium.org/p/chromium/issues/detail?id=1395079&q=dropdown&can=2

The effect felt on the VTEX admin is, that chrome v108 users are having trouble in selecting from dropdown menus, for instance, on the SKU configuration tab, when attempting to select a value on the dropdown menu, no actions are generated (the entire list of possible values should be shown):

Using chrome's latest version, v 108.0.5359.95, try entering a dropdown menu using the myvtex admin version.

There's a plethora of workarounds, such as:

1. Using other browsers
2. Acessing the same UI via vtexcommercestable.com.br
3. Cahnging the value via API: https://developers.vtex.com/vtex-rest-api/reference/catalog-api-get-product-specification