The Q:

Through the various interactions with Q, we know that the Q continuum is OLD. So old that Q says that the Q have always existed.

While we know that the Q are old, the behavior of Q in the 24th century is not that different than that of a teenager.

If we look at Trelane possibly being a Q, then in the 22nd century they would be like children.

The jahSepp:

While it is possible that the Mycelial network has always existed since the creation of the universe, it is not until the 22nd century that the jahSepp seem to become aware of being existing outside of the network when Discovery begins using their spore drive.

If we look at the jahSepp and Q, they share a lot of the same capabilities but the Q is more "refined".

For example:

1. Able to move from one location to another very fast.

2. Able to make people see them, initially only Tilly can see May but it is possible they later refined this.

3. Able to destroy/create matter at will, initially within the network they break down any matter that makes its way in but with Culber they learn the "secret" of creating matter outside the network.

If the jahSepp and Q are one and the same, it could explain a few things such as:

1. The Q not allowing humans directly into the continuum. They say that humans would not be able to "perceive" the continuum and so always create "illusions" to translate with. This could be because in the network human matter would be broken down, but if there is a "bubble" of actual matter for the humans to exist in, then it may be able to hold up for a while.

2. The interest that the Q seem to have for humanity, as humanity was the first contact the jahSepp had with beings outside the network.

3. The ability of the Q to appear to be omniscient or omnipotent, since they have access to the multiverse they can see in other universes how things turn out and are actively trying to keep this universe on a specific path.

So overall it may be possible that the jahSepp are an early version of the Q and once they learn of beings outside their realm and gain more control over their abilities, they are then able to go out "exploring".