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I would go for the one that is designed for incubators...
how large is the difference between them?
do you have a fan inside the incubator?
most temp sensors etc have a sweet spot. That's the spot they are calibrated to be the most accurate. A meat thermometer needs to be spot on at a higher temp so I wouldn't be to concerned if that was of a few degrees.
The digital on the incubator is accurate if it can get a good sample to test. The problem is that the fan normally blows over the heater and straight on to the probe before it gets a chance to mix. They like to install the sensor that's convenient for the user (e.g its in the lid with the rest of the heater) rather than installing it in the best location so I would expect that to be a touch high.
depending on the quality of the remote temp probe that may be the most accurate. A human glass type thermometer would be the most accurate as its calibrated close to the sweet spot but it only records the highest temperature then it has to be shaken to reset it.
Good news is that a few degrees air temp is with in hatch limits so don't panic. The best test you can do is a shot glass of water with a human thermometer wrapped in cling film (it will be real slow before you can get a good reading as the water has to warm up). The idea is the water reacts like the liquid in the egg. Air temp can swing many degrees but the liquid temp will react a lot slower.
Most important ...........eggs will hatch at lower temps they will just be a little late . At 99.5 they should hatch on time. up to about 102 they will hatch a little early, Over 104 they tend not to hatch. Over 110 they are cooked (internal temp of egg).