Strange section on nem

[Eskew77]

For the last 5 days I’ve noticed this section (circled in the picture) on my RBT. Over all it is healthy and looks good, but this is the first time I’ve seen this happen.
Has anyone seen this before? Is it a weird split happening?

 

[Dom]

just an area less inflated that the rest. Continue to monitor.

 

[Eskew77]

just an area less inflated that the rest. Continue to monitor.

Thank you for the response. I figured it was something that is fairly common and will keep an eye on it. I just wanted to see if someone was gonna chime in and tell me get it out it’s gonna contaminate the whole tank.