Here is one of the emails and summary I sent to support@mycelium.com concerning the issue on Mycelium wallet and some of the possible solutions I tried, anyone with similar problems or solution should please share:

Hello

I am writing to express my deep frustration and disappointment regarding the ongoing issue with my Mycelium iOS wallet, which has remained unresolved for over six(6) months.

Every 13th of the month, the app prompts me to verify my account using my 12-word master seed phrase. I have entered the correct backup phrase—separated by spaces—as required. Despite this, the app repeatedly states that the phrase “does not match this wallet.” I still have access to the account, which confirms that the seed phrase I’m using is correct.

Additionally, when I attempt to send funds, the transaction ID returns an “Invalid BTC Transaction” message on the blockchain. This suggests a serious issue, either with access integrity or wallet functionality.

More alarmingly, when I use the recovery seed on the Android version of your app, it displays transactions from four years ago and a significantly different account balance—completely inconsistent with my current account.

All evidence points to a serious breach or malfunction on your end. At this point, I no longer believe this is a technical glitch. It appears I have been locked out of my wallet, and I have reason to believe that my funds have been misappropriated.

Let me be clear: I will not allow this matter to be brushed aside. My legal representatives are already reviewing the situation, and your organization will be hearing from them shortly. I intend to pursue this until I recover my funds in full—and more if necessary.

The lack of support and transparency from your customer service team is unacceptable. I urge you to take this seriously and respond promptly with a resolution.
Sincerely,