I think I lost the crypto I had in my stormgain exchange account (StormGain has migrated its operation to the platform powered by YouHodler)
From now on I think I will only use exchanges that are on the top 50 or 100 by volume... or if you have other suggestions/filters when choosing an exchange?
Even if you use the number one ranked exchange, what happened to you will repeat itself, maybe in a different way.
KeepingIt's not safe to keep funds on exchange
is not safe. Self custody is best, only keep small portion on exchange if you're a daily trader.
About your predicament. From what I saw online the migration has been successfully carried out and if for whatever reason you did not see your funds, contact YouHodler.