Since the release of Google Charts API version 50 on the 11th of April 2021, a small number of users have reported that their charts show the error "b.split is not a function", and two users have reported the error "Cannot read property 'offset' of undefined". The errors occur in multiple chart types but only on a small number of sites.
These errors are not caused by Plotalot. The same errors occur on multiple sites using Google Charts without Plotalot.
The quick fix is to use the latest version of Plotalot and set the Component Option, "Specific API Version" to 49. This will fix the problem, but it's not a desirable long term solution, since it does not allow your charts to progress to newer versions of the Google Charts API, which continuously introduce enhancements and browser fixes.
A much less desirable solution may be to upgrade to MooTools 1.6, which does not cause any problem with Google Charts (Joomla 3 ships with MooTools 1.4.5). This is not an easy job, and it might well break the extensions that use MooTools. We don't recommend this approach.