As part of portfolio import, I came across a situation where it is not possible to add (even manually) stocks that were previously normally tradable, but are no longer, therefore they are not included in the portfolio overview at all and it is not even possible to include them there, to add them.
For example, these are:
AVAST (merger with NortonLifeLock)
TELEC (O2 C.R. - end of trading)
·