Each WBETH represents 1 BETH plus all of its accrued ETH2.0 staking rewards starting from when WBETH's conversion rate was initialized on 27 Apr 2023 00:00 (UTC+0).
Consequently, the WBETH price denominated in BETH is always larger than 1. That is why when you convert 1 BETH to WBETH, you will get less WBETH.
As rewards are paid on the underlying staked ETH, the WBETH price denominated in BETH (conversion rate) will increase over time. Each WBETH will be worth more BETH.
For example
1. User wraps 1 BETH and gets 1 WBETH on the first day when WBETH launched;(1 WBETH = 1 BETH);
2. As rewards accrue, 1 year later, the WBETH price goes up by 5%;
3. User unwraps 1 WBETH and gets 1.05 BETH (1 WBETH = 1.05 BETH);
4. Now, when another user wraps 1BETH to WBETH, they could get ~0.95238095 WBETH (1 WBETH = 1.05 BETH).
When you wrap the 1 BETH at step 4, it is normal that you get WBETH less than 1. If you unwrap it immediately, you will find you receive an amount of BETH exactly the same as the original one before you wrap.
However, if you choose to continue holding WBETH:
5. 1 year later, as rewards accrue, the WBETH price goes up by another 5% (1 WBETH = 1.10250000 BETH);
6. You unwrap 0.95238095 WBETH and get 1.05 BETH.