Tommee Tippe Prep Machine dispenses too much water

We have been using the TT prep machine for 6months without any issues. All of a sudden I noticed it was dispensing too much water and with a smaller hot shot. I tested by making a 7oz bottle without adding formula and it only did a 2oz hot shot and added 5.5oz of cold water, total water came to 7.5oz.

Now I can get around dispensing too much cold water by pressing the button to stop the water when I need to.

Questions:

Has anyone else experienced the same with their TT machine?

How much hot shot should the machine dispense? I've searched all over the Internet but someone somewhere surely has a list of hot shot amounts per 4oz-11oz bottles?

(It is 18m old now so out of warranty. Doubt TT will help)

Thanks in advance 😊