Reverse Beacon Network Questions

[Strange Beacons]

I posted this over on the Amateur Radio subReddit, but didn't get any response. I'm hoping someone here might be able to help me out.

I have been using the Reverse Beacon Network (RBN) for many years, mostly while transmitting Morse code. It works great for Morse and my call sign shows up on RBN every time that I transmit.

Recently I have been transmitting many RTTY sessions using FLDIGI. But, I have never seen my call sign register on RBN, even after hours of sending out signals. Yet, while monitoring my own signal, I often see other call signs I'm decoding on my FLDIGI screen register on the RBN. Yet my call sign never does, even though I am transmitting on almost the exact same frequency and at the same time as RTTY call signs that do. (One call sign I checked last night that registered was located in New York and the skimmer that picked up the New York call sign was located in Europe. (My own location is in Florida).

Does anyone have any idea why my RTTY signal is not registering on RBN, while my CW/Morse signal does?

I'm not really savvy as to how the network of RBN skimmers are set up. Do all of them register/copy the same modes, i.e., Morse, RTTY, PSK31, etc? Or does a particular skimmer only copy certain modes? Like CW only. RTTY only, etc.

I'm asking this because I'm thinking that maybe there are more CW skimmers located in the United States, while there are more RTTY skimmers in Europe (I know from experience that more Europeans use RTTY than do those here in the States).

Can anyone help me out here? It is kind of driving me nuts! Thanks.

UPDATE: OK, I discovered that the Reverse Beacon Network had a contact page, so I sent them an email asking the same questions as I lay out above. One of their spokespersons contacted me and essentially validated what I suspected above, i.e., that there are more CW skimmers in the United States and more RTTY skimmers in Europe. So, it appears that my RTTY signal is not broadcasting far enough to ring any bells on the skimmers there.