The dropdown input field needs default placeholder text. which will correctly set field height.
Created attachment 1642664 [details] Empty dropdown field
Created attachment 1642665 [details] Missing placeholder text
Tested on ocp 4.3 with payload 4.3.0-0.nightly-2019-12-08-215349. Install operator "AMQ Certificate Manager", create instance with "Edit Form", check the creation page, there is placeholder in "Key" Algorithm" dropdown box. The bug is fixed, so move it to Verified.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2020:0581