settings won't be saved after wordpress transfer

Hi! Everything worked perfectly up until I transfered site to another server. Since then, settings won’t be saved… I get a communicate Saved successfuly and the values are changed on the page, but they don’t change for the slider.
I don’t really know what to do or what the cause might be. I thought there might be some sort of misdirection after the transfer since I did it manualy. I would like to know what may I check that may cause this.
Weird thing is that the changes for the slides were saved! It was only general settings that refuse to.
Any help would be appreciated. I really like this plugin ??

https://www.ads-software.com/plugins/master-slider/