Denialists of all kinds will figure some way to attribute it to the global conspiracy that is Science, since they beleive it's all fake anyway. This includes "flat earth" and "geocentrism" spcifically (check out you-tube if you don't know to what extent these people exist!) and various religious fundamentalists who believe that the rest of the universe does not exist.
Most people don't have direct knowledge of the positions of the planets and won't care, or won't beleive that such a thing happened, and won't understand why astronomers are sure.
GPS sattelites are included in the freeze, so that should still work. Communication sattelites and others in geosynchronous orbit will be messed up. At the cery least, adjustments and calibration will be needed. In some cases, the satellite will not be recoverable.
Spacecraft elsewhere in the solar system will be on its own for that time. They might include saved data relating to the earth. Look at solar observatories in particular.
Was the freeze actually a protective stasis shield? If outside evidence is seen (e.g. on the moon) and the solar observatories are fried, it could point to a solar event or a nearby gamma ray burst. Maybe a fresh supernova reminant can be seen. Maybe it was for a would-be impact event.
Even if there is no such evidence, that would be a hypothesis that is floated by non-religious and beleived on faith by a new class of nuts.
If this was indeed done for Earth's protection or benefit, why 5 months? That will jump to a different season and mess up the weather and ecosystems. It would be less disruptive to jump an exact year, or briefly. In fact, if it was an exact year you might wonder if it's happened before but was largely unnoticed in pre-technical times.
Why would an omniscient being do that? If it's for protection, why not just prevent or divert the disaster directly? True religious folks don't grasp the paradoxes or imagine the laeger picture and treat "omni"scence as within their own narrow human viewpoint, which is far from omniscient as one can get. If it's just because, the issues of why? are deeper.
Consideration might be given to the one real effect — the jump in seasons — as being the purpose.
Skeptics and non-believers will look for an explaination of über-technology rather than something ouside the laws of physics (supernatural). The idea of "the world is a simulation" may also be advanced to justify the existence of supernatural.
If the various religious populations don't destroy everything fighting over which god and what command tomus is infered, it could lead to a WW-II style technological explosion, as people put resources into better understanding what is possible and how it all works, and searching the cosmos for more clues.
Rather than giving a reason up front, a good story would be to have different culture and groups react in different ways, and write about those.