Tiny bubble located on 7 foot square of the wall

[Paxcou]

I have replaced in June my liner due to a leak I have dealt with in March/April.
I have also changed the filter gasket in June. I have to modify few pipes. I have a very tiny leak located around the pump but it's extremely small and does not affect at all the water level in the pool (one pipe is slightly too long and put a bit of pressure on the junction between the pipe and the pump, I have to fix it). I have also added a "chlorinator" that sends 75 ounces of chlorine everyday at 1pm. I do not use pool heater.

Everything seems to be fine, and work beautifully. The last test I have done are below.

I have however noticed a strange behavior: on a small section of the wall, always the same (probably around 7 foot square of the wall in the higher end of the pool located on the wall where the jets are), I have very tiny bubble on the wall that I can wiped out in a movement of my hand.

What this could be and if it's an issue what should I do ? Is it related to any of the information I have shared above ?

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Iroquois drive
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Build Type: Vinyl
Volume: 16000 gallons
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Latest Test Result Summary:
FC: 7.0 (3 days ago)
CC: 0.0 (3 days ago)
pH: 7.5 (3 days ago)
TA: 80 (3 days ago)
CH: 70 (3 days ago)
CYA: 40 (14 days ago)
TEMPERATURE: 82° (3 days ago)
CSI: -0.76 (3 days ago)
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[ajw22]

With all the rain NJ has hit the ground is saturated. I would not worry about a bit of ground water causing a bubble. See what happens to it if we ever dry out.