Why MX record is not updating the correct A record

I've notice about cache in the ISP's but i wish know more about this and how to deal with that.

I have more of 24 hours waiting my MX record update to the correct IP. Look this:

I have an 5 priority for mail.vuelosenglobos.mx and the IP Adress it's wrong, and for the 10 priority record the IP it's correct.

Is this a cache issue or it's something else which is causing the first record it's not updading this IP Adress correctly? Actually my domain descubreteotihuacan.com it's working very well, but the MX record doesn't.

This is my DNS records of my domain:

This is the DNS records of my hostname

I have for descubreteotihuacan.com domain an TTL of 3600 which is 1 hour i want to update it. Sometimes i think i need to update also the TTL of my hostname mail.vuelosenglobos.mx but first i want to make sure it's nothing else.

Thank you.

It's very important to tell you i use no-ip DNS service because i have dynamic public IP address so that's why i definitely don't use an specific public ip.