Yep, sounds familiar to me too.

I've sometimes left the bass untouched for a month or two, and when I start again I've improved, maybe not too much in the technique but about the musical knowledge. During your breaks, you listen to more music and collect ideas. As long as the breaks are short, your technique might develop too as you might think about that riff you couldn't do earlier and try to figure out how to do it. And if you have been exercising (gym, sports etc), you know your muscles and endurance don't develop without breaks. This probably applies to the finger muscles used in bass playing too.
I don't suggest anyone to leave their bass untouched for several weeks or months, but just to take the time to really
listen to other music in between is really helpful.