@gimarwb17_ESO

First, in my experience, any game that I buy from Steam and subsequently download and install is stored on my computer within a Steam folder tree -- along with other games which I bought from Steam, then downloaded and installed.

So, that is a different location than the location where the software will be installed (stored) after buying the same game from the publisher or a retail distributor. Any expansion or DLC (regardless of the source from which you obtain it) for a game bought from Steam must be installed in the same location as the original game files. Personally, I would never buy a MMORPG from Steam. Albeit, they have been a reasonably satisfactory channel for obtaining solo-player games.

Before spending money to buy The Elder Scrolls Online again, I recommend that you read the following Support webpage for instructions to "link" your Steam account to your ESO Game account -- assuming that you have not "linked" them:

How do I make my Steam version of The Elder Scrolls Online Steam integrated?

How arduous and difficult doing that might become depends upon the version of the software that you bought from Steam. Afterward, to play TESO, you simply log-in to Steam and select TESO from your game library.

That said, whether "linking" the accounts has any particular benefit(s) or advantage(s), I do not know. It may or may not resolve the issues which you have encountered.

(EDIT)

.... But now I read some were able to keep their chars if they buy the game for $10 from Zos and do a lot of other stuff (I copied it and will try it)

Frankly, I have no idea whether you can buy TESO "base game" for $10 whether from ZOS or a retailer, but be careful with that "other stuff". On the face of it, I would not attempt to change the Steam TESO installation except as a last resort.

All data for each player-character is recorded by the ZOS megaserver. As far as I know, the game client which Launcher runs is the same regardless of whether you initiate the game by logging in to Steam, or by running Launcher directly. So there should not be any problem with continuing to play your current characters, after you switch to playing with software obtained from ZOS instead of from Steam. But I cannot guarantee that ZOS has never created one, whether they've fixed it since. (END EDIT)

Second, remember that the Morrowind and Summerset chapters (and the upcoming Elsweyr chapter) are separate additions to the original The Elder Scrolls Online "base game" software. Numerous Downloaded Content (DLC) packages have also become available since the original TESO was released. Each chapter, and each DLC, is available for purchase with Crowns from the in-game Crown Store. (Of course, I assume this is true regardless of whether a player logs-in via Steam or via their ZOS game account.)

1. At the top of the forum page on which you are reading this reply, there is a black "banner" which has an image of a flag on the left end, followed by links to Game, Account, Store, Forum, and Support, respectively.
   
2. There is also a prominent BUY NOW button on the right end of the banner. Use that button to display a page where you can buy the software according to what you want and need: Join Us.
   • The ESO Standard Edition currently includes the Morrowind chapter with the "base game".
     
   • The Elder Scrolls Collection currently includes the Morrowind and Summerset chapters with the "base game". It also includes 4 DLCs (but I don't know which ones).
     
   • Note that, if you purchase a monthly ESO Plus subscription via your Game Account, then your character(s) will have access to all of the DLCs that have been, and will be, released while the subscription is in effect. Perchance ZOS has a problem with your game account, though, and cannot bill the subscription or has failed to record it, then you won't have access to DLCs that you have not purchased until that problem is resolved. (Of course, if you cancel the subscription, then your characters will not have access to any DLC that you have not purchased.)

Be aware that you must install all such software separately from your current installation via Steam. Installing a purchase from ZOS will license you to run the game software, so you will not need to log-in to Steam to play TESO.

After you install the currently-distributed version of The Elder Scrolls Online "base game" with any chapters and DLCs which are included, the Launcher will probably download and install one or more updates to them.

Which is to say that completing and updating the installation is likely to take a significant amount of time.

If you previously purchased any DLCs (such as Wrothgar and Imperial City), then re-install them to your fresh TESO installation in its new location after the "base game" installation is finished. Again, after each one is installed, the Launcher will update it. As noted above, you can buy and download the respective installation filesets for other DLCs, or choose to pay monthly for access via the ESO Plus subscription.

Good luck, and happy gaming!