The market may be at a record high, but not all ASX dividend shares are soaring.

For example, two popular shares that have underperformed the market are listed below.

Let's see why analysts think that now could be the time to double up on them:

Telstra Group Ltd (ASX: TLS)

Telco giant Telstra is one of the most popular ASX dividend shares out there.

But with its shares underperforming the market significantly over the past 12 months, now could be a good time to consider either investing or adding to existing positions.

Goldman Sachs certainly thinks that is the case. The leading broker believes that Telstra's positive outlook and attractive dividends make it an attractive option right now. It recently said:

We believe the low risk earnings (and dividend) growth that Telstra is delivering across FY22-25, underpinned through its mobile business, is attractive. We also believe that Telstra has a meaningful medium term opportunity to crystallise value through commencing the process to monetize its InfraCo Fixed assets – which we estimate could be worth between A$22-33bn.

In respect to dividends, Goldman Sachs is forecasting fully franked dividends of 19 cents per share in FY 2025 and then 20 cents per share in FY 2026. Based on the current Telstra share price of $3.95, this represents dividend yields of 4.8% and 5.1%, respectively.

Goldman has a buy rating and $4.35 price target on its shares.

Transurban Group (ASX: TCL)

Another ASX dividend share that has underperformed the market this year is Transurban.

It is a toll road operator with a portfolio of important roads across Australia and North America. This includes the CityLink toll road in Melbourne, the Cross City Tunnel in Sydney, and AirportlinkM7 in Brisbane.

Bell Potter thinks it could be a good time to load up on Transurban's shares. So much so, it has the company on its Australian equities panel. These are the broker's top monthly picks and investments that it believes offer attractive risk-adjusted returns over the long term.

Commenting on its bullish view on the stock, it said:

We believe the current inflationary environment is favourable for Transurban given its inflation-linked revenue stream with annual escalators. Moreover, TCL provides low risk cash flows over the long term, with long concession duration (30+ years), and relative traffic/income resilience. The group's current pipeline of growth projects is $3.3 billion (TCL's share of total project cost) and further huge development opportunities are expected over the next few decades, supported by population and economic growth.

The broker is forecasting dividend yields of approximately 5% over the next 12 months and beyond.