Add to description additional text covering the save bonus and add as a conditional save modifier:
An aegis of recovery grants its wearer a +2 resistance bonus on all saving throws made to recover from a continuing effect,
This is not a bug! We try to limit the amount of information about an item that is added to a character's sheet to only that which is likely to be needed in combat regularly. Among the reasons for this is a desire not to become a replacement for owning the actual source. Thus, huge amounts of info on individual items that don't immediately affect character stats, skills, and combat abilities are intentionally left out. While there is a good argument to be made that such information MAY be of use in combat, the person who authored this data set didn't seem to think the ability's limited scope warranted a large block of text on a player's sheet, especially since that text would need to be added to the text already given for the item.
I can work around adding a line to the text but the conditional modifier is missing.