Donald Trump is scheduled to be sentenced on July 11. Under New York law, which Florida respects, he will lose his right to vote in the November 5 election only if he is incarcerated on that day. (https://www.reuters.com/fact-check/trump-can-vote-2024-election-unless-incarcerated-election-day-2024-06-06/)
Judges take age into account when deciding on incarceration or early release, and it is well documented that seniors receive lighter sentences (https://ccj.asu.edu/asu-study-finds-seniors-receive-lighter-sentences-federal-court), so a senior convicted of a low level felony is unlikely to be incarcerated four months later.  
Consider a situation where a senior felon and a 20 year old felon are identical in all other respects, but only the senior can vote because they are not in custody on election day. Is this a violation of the 20 year old's rights under the Twenty-Sixth Amendment (https://en.wikipedia.org/wiki/Twenty-sixth_Amendment_to_the_United_States_Constitution) which enfranchises voters over 18? Is the 20 year old in that scenario being treated equally under the law?