In 2009, Ohio changed the deadline for a qualified party to certify the names of its presidential and vice-presidential nominees from 75 days before the general election, to 90 days before the general election. This was a very irrational act, because it is quite common for at least one of the major parties to hold its presidential convention after that deadline.
In 2012, the first year the conflict existed, the Ohio legislature during 2012 passed SB 509, moving the deadline for 2012 only to 60 days. This was done to help both major parties, because that year the Republican convention was August 27-30, and the Democratic convention was September 4-6.
There was no problem in 2016, because both major parties nominated in July. But in 2020, it would again have been a problem, because the Republican convention was set for August 24, 2020. So in 2019 the legislature again passed a bill setting the deadline at 60 days, to apply to 2020 only. That was in the budget bill, Am. Sub. HB 166, signed July 18,2019.
Now the problem has arisen for 2024, because the Democratic convention is August 19-22. See this story. It says the Ohio legislature may pass a bill changing the deadline. If it does not, the Democratic Party would have an easy lawsuit to strike down the deadline. This is exactly the type of lawsuit in which Trump v Anderson, the U.S. Supreme Court decision of last month, would be relevant. For Ohio to leave the Democratic nominees off the ballot would create the ballot access “patchwork” that the court unanimously felt was bad policy.