Time Capsule wifi connectivity problems

The first thought that comes to mind here is that the average useful life of the Time Capsule is about 3 years. After that time, the device tends to start heading downhill, and any number of issues can start to display themselves.

One of the more common issues as the unit ages is the ability of power supply to remain stable and reliable. Even a short "blip" can result in a temporary loss of some of the network settings on the Time Capsule. Powering off the Time Capsule or restarting it will sometimes help....until the issue surfaces again.....and again.

Frankly, I doubt that it would help to reset the Time Capsule and set it up again, but other than changing the wireless network name and/or password, there is not really much that you can do. Might be worth a try if you have not already done so.

Do you know approximately how old the Time Capsule might be? If you have one of the older "flat" or "square" models that look like a small white pizza box, you can find the model number on the bottom of the device, usually embedded in the foam pad base. The model number starts with an "A" followed by 4 numbers. Post back with that info and we can tell you more about the Time Capsule.

Even the more recent "tower" shaped version of the Time Capsule might be as old as 5+ years depending on when it was first placed into service.

Do I need to make sure that the gateway is still in bridge mode or is there something that I need to do to the TC?

It won't hurt to check, but even if it is not in Bridge Mode, this would not cause the issue that the Time Capsule is experiencing.