Skin does not heal properly after covid contracted/vaccinated? Is it common?

There is still much we don't know about covid in western and Chinese Medicine terms, so generalized answers will be limited.  As usual, the best answer is to see a practitioner locally and get treatment tailored to you as an individual.

That said, one of the things that appears to be happening on some people post covid in changes in the smaller blood vessels.  In TCM theory this -could- be equivalent to some type of blood stagnation/deficiency patterns.  Another aspect, of course, is generalized inflamation either related to some type of ongoing infection (low-level) and/or related to a set of auto-immune/inflammatory processes kicked off by covid.  For example, there are cases of people developing diabetes, arthritis, etc. post-covid.  The full etiology of these events in not well understood.

In proper TCM then, that is why it is important to see someone so they can treat what they see in -you-, not what they expect to see based on a history of a condition - particularly something not well understood such as covid.  

Not as a recommendation, but given the very basics of what you provided, I would be tempted to go more towards a combination such as xiao chai hu tang and xue fu zhu yu wan or xue fu zhu yu wan or xiao yao wan with something like fu fang zhen zhu an chuang wan.  But again, you should consult directly with someone.  If the person had more history of blood deficiency, maybe some blood tonics with light moving would be appropriate, history of immune/auto-immune issues maybe another approach entirely, etc.