Hi everyone. Apologies in advance for a very long message but I am beyond confused and upset about what is going on with my 8 year old female Chi.

In June 2020 my (then) 7 year old Chi stopped eating, had her tail down all the time, slept a lot, had a faster and irregular heart rate, was breathing quicker and had paler gums and ears.
She had blood tests done that were almost all too high or too low so was rushed to an animal hospital. She was severely anemic, high liver readings, etc. It was touch and go at the hospital but she pulled through and eventually came home again.

Her blood tests results were almost all back to normal, and the ones that weren't were heading in the right direction.
In October 2020 I did blood tests again and she was continuing to improve.
In January 2021 I did blood tests again and she was again continuing to improve.

However in April 2021 when I did blood tests some of the results that hadn't fully recovered but were improving, had started to go back the wrong way again. The results were:
ALT 47% higher than top range.
UREA 68% higher than top range.
JAUNDICE 13% higher than top range.

Two weeks later in May 2021 the blood test results were then:
ALT 111% higher than top range.
UREA 100% higher than top range.
BILIRUBIN high.

Five days later in May 2021 she had a liver function test. The results were:
ALT 104% higher than top range.
ALKP 106% higher than top range.
UREA still a little high.
JAUNDICE back to normal.

Two weeks later in May 2021 she was sedated and had a thorough scan of her organs and more in depth blood work. They were happy with the scan and couldn't see any problems. The blood results were:
ALT 15% higher than top range.
ALKP 81% higher than top range.
CK 13% higher than top range.
UREA 51% higher than top range.

She was then put on Samylin (a liver supplement).

Four weeks later in June 2021 she had a liver function test done again and the results were:
ALT 32% higher than top range.
ALKP 112% higher than top range.
UREA 52% higher than top range.
Bile acids now normal.

That is all of her results so far.
The hospital never gave her an official diagnosis last year. My vet thinks it was peritonitis and that part of the liver is scarred or something, hence why the readings are a bit off. He is sure she doesn't have liver shunt as her bile acids are normal.
Apart from the blood tests being too high, the rest of her results have recovered fantastically. She's no longer anemic, white blood cell count is good etc etc. These liver readings and urea readings just won't go down to normal.
When she got ill a year ago she was on Burns food but has since been on Purina Pro Plan Hypoallergenic.
She is a healthy weight and has even been putting on weight, not losing any.
She is a happy dog and has good energy. She doesn't appear ill. Sometimes she may go a little quiet or be a little picky with her food but it is shortlived and could be down to the weather, sleep etc. Overall she appears to be a very healthy and happy dog.

Does anyone have a Chi with similar issues? Or has any idea what my dog's diagnosis might be? Am I missing something? Is there something else I can test or try? Any advice would be greatly appreciated. Thank you.