Yes, it is completely fine to switch during probation. Just have a reasonable and diplomatic answer prepared if current HR asks for the cause of leaving, and future HRs ask the cause of switching so soon. Please don't tell any HR the actual reason, truth doesn't leave a good impression unfortunately.
Also, never resign before having an on-paper/on-email official offer letter. So feel free to keep applying, once you secure a better offer and job role, quit - be it probation or not.
Also just a suggestion, whenever I switch it's for the following reasons- toxicity, salary, learning. If you feel 1.5 months is enough to make the decision to switch, please go ahead. But do give this a thought as well.