Fortunately we do not see evidence of thrips on the foliage in the photos; their feeding damage looks different than this, and they also tend to leave behind frass (a term for insect poop) droplets that look like tiny tar spots glued to the foliage when they are persistent or abundant, which we do not see here. The leaf spotting visible is minor and appears to be only cosmetic damage, not caused by a pest or disease. We can't tell if it's related to exposure to something while it was outside, but it shouldn't be serious.

While plant leaves cannot heal from damage, as long as it doesn't spread or worsen considerably, it should not be of concern. If you do see a change in symptoms, feel free to send us new photos. We have limited experience with which exact pathogens are responsible for certain leaf spots on tropical plants grown locally, but will certainly see if we recognize any damage pictured in that event. In the meantime, as a general rule of thumb, avoid spraying the foliage with anything -- even plain water, since leaf surfaces that stay wet for long periods can allow disease spores to more easily enter the leaf. Phytotoxicity, which is the term for plant tissue damage caused by chemical exposure, can result from the use of certain insecticides, fungicides, and even home remedy sprays (like those that use household soaps or rubbing alcohol, both of which can easily damage leaves).

Your Monstera plant looks very good! Given what we see in the photos, we don't see a cause for concern at this point.

Miri

You are welcome.  We are happy to help and your Monstera is gorgeous!