Hey JD,
I work for a company that provides CNAM (Caller ID Name) data to phone carriers. I'm also very familiar with the robo/spoofed call dilemma that is facing the telecom industry.
As I'm sure you have experienced, people receive a ton of spam calls on a daily basis. To combat this, many phone carriers have implemented nuisance/spam scoring algorithms. These phone carriers automatically flag numbers that show signs of being unwanted calls. Sometimes this is done by blocking them entirely, sometimes replacing the CNAM with something like "SUSPECTED SPAM."
Each phone carrier can decide how they want to handle calls the suspect are spam. For example, if you call my cell phone from Xencall, AT&T (my phone carrier) will decide, based on their internal algorithm, how they want to handle the call. In addition, there is no central database or whitelist that carriers can cross-reference to determine which calls are "known-good" or non-spam numbers. Each carrier is on its own and even if Xencall marks your number as safe or good, other carriers won't be able to access that information.
The only thing I can recommend is testing calleridreputation.com. While I can't speak to how effective it will be for you, you should be able to see how your outbound numbers score within a handful of different carriers and robocall mitigation services. Once you have identified which service/carrier is flagging your numbers, it may be worth reaching out to them directly to resolve.
I suspect 411.com provides a single score and doesn't evaluate many nuisance services when determining if your numbers are low-spam-risk.
Let me know if you have any questions!
