LED bulb issue with flicker and not coming on

We remodeled a few years ago, and at the time I put in LED bulbs in the new fixtures. The two lights that hang over the sinks are on a dimmer, and sometimes when not at full brightness there will be a little flicker. Not really noticeable unless you're looking for it, but now the one by the shower has started it. Except it won't come on all the way. There are two lights on this switch, and it isn't a dimmer. Typical can light over the toilet and a sealed fixture on the ceiling right outside of the shower, so that steam doesn't affect it. At first I thought it may be something with the dimmer, but since this one is also doing it I'm wondering if this is an issue with the bulbs.

I flip the switch, and not every time but maybe a couple times a day now the light over the toilet comes on fine but the one by the shower will flicker and not come on full strength. When I turn it off, it doesn't go off right away and it is very dim then slowly shuts off, for about 5 seconds. Do y'all think this is a fixture issue or a bulb issue? I was going to replace it but not sure where to start.