CDNN SPORTS is having a magazine sale. You can buy a new factory mag for the price of a quality replacement spring from Wolf. It may be time to discard these old magazines. Beretta advises that loaded mags should periodically be unloaded so that the order of the rounds can be changed. Top bullets should be relocated to another position--to prevent case deformation.
Slide release lever spring may require replacing. Is your supporting hand bumping the slide release? Many people will load magazines with one less round regardless of brand.