JS Error – Hidden Fields Not Working

Heya,

We’ve been having an issue with a client’s website and the conditional fields working for some time, but were hoping a newer version of the plugin would eventually address the issue. I’ve searched the support forms and I didn’t find a duplicate of this issue, so hoping you may have some insight.

Below is the error code we receive in the console view:

Uncaught TypeError: Cannot read property 'substring' of undefined
    at Object.get_simplified_dom_model (scripts_es6.js:1180)
    at scripts_es6.js:1215
    at Array.forEach (<anonymous>)
    at Object.get_simplified_dom_model (scripts_es6.js:1214)
    at scripts_es6.js:1215
    at Array.forEach (<anonymous>)
    at Object.get_simplified_dom_model (scripts_es6.js:1214)
    at scripts_es6.js:1215
    at Array.forEach (<anonymous>)
    at Object.get_simplified_dom_model (scripts_es6.js:1214)
get_simplified_dom_model @ scripts_es6.js:1180
(anonymous) @ scripts_es6.js:1215
get_simplified_dom_model @ scripts_es6.js:1214
(anonymous) @ scripts_es6.js:1215
get_simplified_dom_model @ scripts_es6.js:1214
(anonymous) @ scripts_es6.js:1215
get_simplified_dom_model @ scripts_es6.js:1214
wpcf7cf_reload_dom @ scripts_es6.js:72
get_nested_conditions @ scripts_es6.js:1126
./js/scripts_es6.js.Wpcf7cfForm.updateGroups @ scripts_es6.js:442
Wpcf7cfForm @ scripts_es6.js:228
(anonymous) @ scripts_es6.js:1512
each @ jquery.min.js:2
each @ jquery.min.js:2
./js/scripts_es6.js @ scripts_es6.js:1511
__webpack_require__ @ bootstrap:19
0 @ scripts.js:4003
__webpack_require__ @ bootstrap:19
(anonymous) @ bootstrap:83
(anonymous) @ bootstrap:83

We are using a custom WP theme that our team developed. Active plugins are the latest version of the following:
Advanced Custom Fields Pro
Contact Form 7
Contact Form 7 Conditional Fields
Yoast SEO

We use others, but those are the minimal we need to run the website and try to address this error. I can share the link of our development page if that’d be beneficial.

Thank you for your time!