Don't just use any aftermarket RTV silicone sealant! Use Ford F8AZ-19B508-AB red gasket maker or ThreeBond TB1207C, since Mazda doesn't sell red transmission sealant as they don't expect you/recommend you to drop the pan.
You also need a scan tool that can display the TFT (transmission fluid temperature) so that you can accurately measure the fluid. As the dipstick shows in your pic, must be measured at 122 degrees for true accuracy, and even a little bit off can make a big difference! This was mentioned on the BITOG forums long ago and is essential for these sensitive and highly efficient transmissions to function properly. If you don't have a scan tool with this function, you need to get it or just pay a shop to change the fluid for you.
Btw, Ravenol ATF-FZ is a great alternative, as it's the only aftermarket fluid available but also fully synthetic, unlike Mazda's which is dino juice.