While adding liquidity in the pool section, it goes round & round, processing & processing . In the end it gets cancelled & your tokens vanishes from your wallet. Tested through Mobile Phone(Android)
My Venom Wallet Address - 0:b2597d7add6f75743be046fdb04cdc86a7e547acd26ec1afb23af44d1f9dceb5
If I may ask what browser are you using on mobile ? It’s is recommended to venom wallet built in browser for the tasks, it works well that way.
Also, since it is a testnet, there may be errors of long transaction downloads. For testnet this is normal, in these cases you have to wait a little bit. If tokens or fee were withdrawn, but nothing happened - you need to wait a bit. Do not make transactions yet. Tokens will either return to the account, or the job will happen.
Let me know if the above information helps you get through this.