I think the Seeing Numbers with All the Same Digits article contains the answer for you. The reason may be because it is a mystery.

From your question, I understand you see same-digit sequences, but it can be any same-digit sequence. A sequence of 1's. A sequence of 2's. Etc.

Numerology can provide the meaning or essence of individual numbers. Because the digit being repeated in the same-digit sequence varies in your experience, there would be many different meanings.

Which is why I feel the incidences you describe continue because of mystery. And probably also because it's a way to interact with your friend that brings the two of you together even more.

Maybe that is in fact the reason: Something to assist in bringing the two of you together more than you were and, in that way, lead to a greater understanding of each other.

From your numerology charts, I see you tend to look inward for meaningful answers. Your friend is more likely to look for creative answers by asking close friends or looking it up online.

As an aside or FYI, something you didn't ask about — when you and your friend turn 40, or soon thereafter, your power numbers will gain influence. Both your power numbers are 3. It means there is likely to be an increased focus on artistic expression and more inclination to participate in social activities.