[Bug]: Unreliable token value for assets with no fiat conversion when input is in fiat

[bschorchit]

Describe the bug

We should disable switching input to from token balance to fiat in the assets page as this cause incorrect sending values. This is what extension (old send flow) currently does for tokens with no fiat conversion.

Expected behavior

No response

Screenshots/Recordings

ScreenRecording_09-12-2025.17-57-05_1.MP4

ScreenRecording_09-12-2025.17-49-14_1.MP4

Steps to reproduce

1. Start a send for SepoliaETH or Linea LXP or another token with no fiat conversion
2. In the amount page, switch to fiat
3. Input a number
4. Continue
5. Notice the confirmation is sending some token funds even though there was no fiat conversion to allow us to calculate how much to send

Error messages or log output

Detection stage

During release testing

Version

7.55.0

Build type

None

Device

iphone 11

Operating system

iOS

Additional context

No response

Severity

No response

[Unik0rnMaggie]

• unable to reproduce on Sepolia. Blank screen when sending the transaction, after switching to fiat in the send flow
• reproduced partially for USDC token on Unichain. After switching to fiat, the send screen indicates an incorrect amount. The confirmation screen indicates the correct amount

v7.55.0 (2395)

Send.fiat.sepolia.blank.screen.7.55.0.2395.mp4

send.fiat.unichain.7.55.0.2395.mp4