Form values disappear intermittently

Description

Some values in drop-down fields disappear intermittently. In some cases, these are mandatory fields, so the absence of values prevents forms from being submitted This affects live forms that the public is currently trying to access.

This issue is extremely intermittent on all environments (nearly impossible on development, but can see intermittently especially on Azure).

Product versions
EPiServer CMS: 10.1.0 / EPiServer Forms: 4.2.1

Release:
Hotfix in Forms 4.2.2, and also merged into main branch from Forms 4.4.1++