Event Schema type missing of “StartDate” & Other critical errors

Hello, I am using schema markup for almost every post of my blog. Also, by default blog post schema is selected for every post that’s why we do not need to change it if it is just a blog post. But, I often post Scholarships for students and add Event Schema to this. I wanna ask you guys what am I doing right. I put the start and end date the same as when the application for scholarships starts and on the last date I put the deadline. And, select the event as Online and then put the organizer link and Name. But, from the last two weeks, I am facing the issue with Event Schema. Google Search Console gives me Error that StartDate is missing. But I put that start date in the article in which GSC was detecting an error. While this I am also facing issue of SartTime Zone missing error in my other article. But, Rank Math does not show any Time Zone Option.
I also noticed that officially there are many great options in Schema that Google Recommend but Rank Math lacks off. Please guide me that how can I solve these critical errors and also there are many warning which seems illogical because I selected the correct options in rank Math But GSC does not detect them.
The last thing which I wanna ask is that I also provide information about the admissions of Universities and various institutions, Can I put Course schema for the programs offered by institutions. Like if I wanna post about the Master’s program of a university, can I put Course schema in this type of post. Thank You!
Here is the example of a post where GSC showing an error of StartDate missing,
Source to StartDate Missing Error
And, Also, here below I am leaving the link to the error “Datetime property “startDate” is missing a timezone”
Missing Time Zone error