A class tracks the transaction, what the transaction was for in other words.  It does not report on where or how the transaction originated.

You paid an expense, the class reports on that expense
but not whether you paid by bank, cash, or credit card, or even a loan – the source […]

Resolution for 'analysis issue: 'Balance sheet class analysis' available: Yes.

The analysis issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the analysis issue yourself by looking for a resolution described in the article. If it is a complex analysis issue or you are unable to solve the issue, you may contact us by clicking here or by using other analysis support options.

For more information about resolving issues related to analysis in Quickbooks/QBO or to get support for the issue 'Balance sheet class analysis', click the link below: