Hi Wobaguk,
Back in the early 1980's I was on a running coaching coarse in London.
The British Athletics team Physiotherapist Vivian Grisogono was one of our speakers.
there had been a spate of Achilles tendon injuries in the Athletic world then.
She explained the symptoms and how to protect against them.
The most common cause was the tendon rubbing against the heel tab of the shoe leading to a thickening and weakening of the tendon. The easiest prevention was to cut down either side of your heel tab so that the tab didn't press or rub against the tendon. The heel tab at the time was, I think, named in advertisement blub as a "heel tector" giving you the false impression that it protected the heel or tendon.
The fashion for this was brought over from the football world where it had become very fashionable, along with ludicrous mullets
She showed us how to cut down all our shoes. I did this with every running shoe I ever bought and advised friends and my athletes to do the same. I coached all events, including sprints and jumps and In the seven years I coached, none of my Athletes had an Achilles injury.
I asked her why this wasn't highlighted and changed as only one company Karrimor, designed a shoe with a dip at the tendon.
Her answer was she suspected that they would have to justify the fashion change and come clean as to why the shoes needed to be changed and the litigation costs would be to high.
First sign of problems is the tendon will thicken slightly and will feel tender when pinched in behind it.
Good luck with your injury.
See link attached
https://www.viviangrisogono.com/achilles-tendon/achilles-tendon-pain