Alternate frequencies is not actually working

Just had a DPA activate and the APs did not automatically switch to a new freq

Did the DPA affect all your grants or just some of them? If only some are suspended, and at least one remains authorized, the AP will continue using the authorized grant(s). This results in a smaller channel BW until all grants are authorized again.
If all the grants are suspended, the current code does not trigger the search for an alternate channel just yet. That will happen in the next release.

The whole bottom 100 Mhz was triggered so it stopped transmission on 2 APs 1 that had never been effected by a DPA before.

The activation of all 100 MHz is not common, but it can happen. The SAS is in full control of channel activation and de-activation. If you have questions or concerns regarding DPA activations in your area, you can reach out to your SAS directly.