If it drops to that voltage instantly when you unplug, you do have a problem. If you don't leave it on the charger overnight, start doing that fairly often.
On a brand new, perfect battery, it should hold it's full voltage even overnight. But that doesn't last long.
3.5v per cell is the target for fully charged, Hopefully, you'd have that voltage after a full charge, and riding the bike 50 feet. That's 28v. Anything above that is a slight overcharge that helps the battery balance, and has no real useful power in it. As a battery ages, that will get less too, but if you have 27v in the first block, that is still usable.
If your battery has dropped to 26v after a mile or so, that's not abnormal. Lifepo4 will drop some volts in the first mile or so, then it should go a fairly long distance with much less voltage drop from then on. Finally, just before it runs completely out, the voltage will drop fast in the last half mile.
Look at a lifepo4 discharge curve graph, drop at first, then a long flat spot, followed by going over the cliff at the very end. If you have that long flat spot at 26v, that's fine.
FWIW, that battery level indicator you have is pretty much useless to you for lifepo4. They work better with lead, or limn, or lico. But all lithium has a flatter discharge curve, so just looking at voltage tells you little.
To really know what is going on, add a wattmeter to your bike.
