First, if Rank Math took you 10 points of the performance score, you should investigate this further or get rid of that / substitute it.
It all depends on your hosting setup and the plugins you use.
Can you tell us some more details about your configuration? I remember you are on Gridpane.
Which plan do you have and which server do you use?
How to you optimize your site? Kind of caching? Plugins, etc.
I assume this is your mobile score, still it looks very odd to me, you have just a bit over 60.
Yeah, it can be very challenging to get good mobile scores but so many opportunities for improvements there!