The Django 3.2 approach is using pure old template mechanics which will rely on the TEMPLATES setting so will search project dirs (if specified there). It’s the 4.0 form rendering support that uses the FORM_RENDERER setting with a perhaps surprising default that does not use the base TEMPLATES setting.
The error message is trying to convey that codermatch/formSnippet.html can’t be found, not that there is any problem with its content. It’s not trying to indicate a problem in the specified template, it’s trying to say it cannot find the specified template.
Also: Django is searching for templates in the venv because there are apps in INSTALLED_APPS (django.forms and django.contrib.admin) with template directories to be searched.